karat | gold measurement | Britannica.com gold measurement electrum Karat, also spelled Carat, a measure of the fineness (i.e., purity) of gold . It is spelled carat outside the United States but should not be confused with the unit used to measure the weight of gems, also called carat . A gold karat is 1/24 part, or 4.1667 percent, of the whole, and the purity of a gold alloy is expressed as the number of these parts of gold it contains. Thus, an object that contains 16 parts gold and 8 parts alloying metal is 16-karat gold, and pure gold is 24-karat gold. This system of indicating the relative proportion of gold originated with a medieval coin called a mark . A mark weighed 24 carats (in this case, the carat was the same as that used in the weighing of gems and was theoretically equal to the weight of the seed of the coral tree).

Pure gold could not be used to produce marks because it was too soft, so copper or other metals were added to produce a hard alloy; the purity of the coin was then expressed by the proportion of its carat weight that was actually contributed by gold. Learn More in these related articles: in gold processing: Assaying In the jewelry industry, gold content is specified by karat. Pure gold is designated 24 karats; therefore, each karat is equal to 4.167 percent gold content, so that, for example, 18 karats equals 18 × 4.167, or 75 percent gold. “Fineness” refers to parts per thousand of gold in an alloy; e.g., three-nines fine would correspond to gold of 99.9 percent purity. 2 References found in Britannica Articles Assorted Reference Corrections? Updates? Help us improve this article! Contact our editors with your feedback. MEDIA FOR: You have successfully emailed this. Error when sending the email. Try again later. Edit Mode Submit Tips For Editing We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.

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The weight of gold is measured in troy ounces (1 troy ounce = 31.1034768 grams), but its purity, or "fineness" has been measured in a few different ways: "parts fine," "% gold", and karats. (A major point of confusion is between "carat," which is a measure of weight for precious stones, and "karat", which is a purity measure for gold. The terms are used distinctly, even if they have the same derivation.) According to at least one source, the terms karat and carat derive from Arabic and Greek words meaning "the fruit of the carob tree." Apparently, the seeds of the fruit, remarkable for their consistency, were used to balance the scales used by merchants at ancient bazaars[ 1 ]. Karats now refer to the ratio of gold found in a sample. There are 24 karats, so pure gold is 24 karats. The percentage of gold in a piece is therefore the number of karats/24. Thus 96.5% gold is 23 karat (23.16 to be exact).

The legally permissible "karatage" for an item to be called gold historically has differed from country to country. In the U.S. 10k is the legal minimum accepted standard of gold karatage, with 14k the most popular. 14k gold is also commonly found in cases where strength is important, like in earring backs and bracelet clasps. In France, Italy and Switzerland, 18k is the lowest permissible standard to be called gold. England accepts 9k gold, while in some countries of the world, 8k is the legal minimum standard. 15k was the old Victorian standard, and dental gold is 16k. Millesimal fineness Fineness represents the purity of precious metals expressed in parts per thousand.

24 K = 99.9% Pure (European Marking Fineness 999) 22 K = 91.3% 18 K = 75% Pure (European Marking Fineness 750) 14 K = 58.5% Pure (European Marking Fineness 585) 10 K = 41.7% Pure (European Marking Fineness 420) Some countries insist that there is no negative tolerance allowed (e.g. UK, where 18 carat is 750 fineness minimum) but in others a negative tolerance, typically 3 parts per thousand, is allowed (e.g. in USA, a fineness of 747 would be accepted as 18 carat). This causes difficulty in the mutual recognition of national marks/hallmarks , a problem raised in the European Union by the Houtwhipper ruling recently. Thus a piece of jewellery assaying at 747 fineness would pass in the USA as 18 carat but fail in the U.K. 14k averages at about 55% purity rather than 58% in the USA.

.375 = 9K (England and Canada) .417 = 10K .999 (1000) = 24K pure gold Bars The purity of gold bars (gold bullion) is usually expressed as a decimal figure ranging from ".0" (no gold) to .9999 (totally pure). London good delivery gold bars (weighing approximately 400 ounces each) must assay at least 99.5% pure gold; that is, 995 parts of gold per thousand parts of metal, or “995 fine“. Some gold coins and small gold ingots are made from gold that was refined up to 99.99% pure gold; that is, 999.9 parts per thousand, generally stated as .9999, or four nines. What does 750 stamped on jewelry mean? 750 on a piece of jewelry signifies 18k ie 75% pure. It is common in Europe. What does 585 or 583 stamped on jewelry mean? 585 or 583 on a piece of jewelry signifies 14k.

Technically 14K should be 583 (14/24 = .583333) but most manufacturers have adopted the European way and make 14k gold a tiny bit over 14k, so the mark is 585 in most 14k jewelry. What does “LU-RAY” mean? This signifies the jewelry is made from low grade Lurithium Rayon, a cheap substitute for gold. Abbreviations K, k, KT, Kt, kt, CT, ct are all abbreviations used for karat or carat KP, kp Karat Plumb, Plumb is used to guarantee gold content is not less than shown. Thus 14KP means that it is exactly 14K. Otherwise there may be some negative tolerance. K.P. Karat plate GP, gp, G.P. Gold Plated- refers to a metal item that has a very thin layer of 10k gold or better applied to it. The thin layer normally wears away more quickly than gold in a gold filled item. It has a very thin layer of gold bonded to a base metal core.

The layer of gold in gold-plating is only required to be seven-millionths of an inch thick. GF, gf, G.F. Gold Filled ( also called Gold Overlay) - refers to a layer of at least 10-karat gold that has been permanently bonded by heat and pressure to one or more surfaces of the support metal, then rolled or drawn to a prescribed thickness. The karat gold must be at least 1/ 10 of the total weight. The layer of gold in gold-filled items is about one hundred times thicker than gold-plated items. Newer items contain markings that indicate how much and what type of gold was used in the layer. A marking of 1/20 12K G.F. means that the piece is at least 1/20th 12K gold by weight. In gold-filled products, the gold layer must be at least 1/20th (5%) of the overall product, by weight. Any purity of gold may be used; most gold-filled products are made with 12k or 14k gold. The purity of gold used can be determined by the notation in front of the words gold-filled.

14/20 Gold-filled and 14k Gold-filled both refer to a gold-filled product in which 14k gold has been bonded to the base metal core. Likewise, 12/20 Gold-filled and 12k Gold-filled indicate that 12k gold has been bonded to metal. The French term for this is doublé d'or. GS Gold Shell HGE, H.G.E., hge Heavy Gold Electroplate, is also sometimes called Vermeil. Vermeil consists of a base of sterling silver coated or plated on all significant surfaces with gold, or gold alloy of not less than 10 karat fineness, that is of substantial thickness7 and a minimum thickness throughout equivalent to two and one half (2 1/2) microns (or approximately 100/1,000,000ths of an inch) of fine gold. KW White gold MIL 1 thousandth of an inch. Refers to thickness of gold plating. MILL 1 millionth of a troy ounce. JSN, PR, HJ These are all maker or design marks and have no relevence to the value.

HJ is short for Heriff Jones . pall Palladium plat. Platinum RGP, RG stands for rolled gold plate or rolled gold. This means that it is gold filled. WG White gold YG Yellow gold YLTM Yellow Lustrium. Lustrium is a mixture of nickel and chromium. Yellow lustrium is fused with an amount of real gold all the way through so even if scratched, there will not be a difference in color. The gold content is higher at the surface, and becomes less, deeper into the metal. The cost is lower than 10kt Gold. 316L - High-grade Stainless Steel Units: K the Japanese name for the nautical mile . kanal a traditional unit of land area in Pakistan, equal to 20 marlas . Under British rule the marla and kanal were standardized so that the kanal equals exactly 605 square yards or 1/8 acre ; this is equivalent to about 505.857 square meters. kappland a traditional unit of land area in Sweden.

The kappland is equal to 1/32 tunnland or 1750 square Stockholm feet (kvadratfot); this is equivalent to 154.26 square meters or about 184.50 square yards . karat (kt) [1] a traditional unit of mass for precious stones, now spelled carat in both Britain and the U.S. karat (kt or K) [2] a traditional measure of proportion equal to 1/24, used by U.S. jewelers to express the purity of gold alloys. Thus "14-karat gold" is legally required to be at least 14/24, or 58.3%, gold. In Britain this unit is spelled carat, like the weight unit for diamonds and other precious stones. American jewelers apparently spell the unit of gold purity with the "k" and the weight unit with the "c" in order to distinguish more clearly between them. (In German, both units are spelled with the "k".) kare meter or karemeter a name for the square meter used in Ethiopia.

katal (kat) a unit of catalytic activity used especially in the chemistry of enzymes. A catalyst is a substance that starts or speeds a chemical reaction. Enzymes are proteins that act as catalysts within the bodies of living plants and animals. A catalyst has an activity of one katal if it enables a reaction to proceed at the rate of one mole per second. The unit, pronounced "cattle," was added to the International System at the 21st General Conference of Weights and Measures in October 1999. kati a traditional Malaysian unit of weight, usually spelled catty in English. kattha or katta a traditional unit of land area in South Asia, equal to 20 dhurs or 1/20 bigha . Like the bigha, the kattha varied in size from one region to another. In Nepal, where the unit is still in use, the kattha equals about 338 square meters or 442 square yards. kayser (K) (1) a CGS unit used to measure light and other electromagnetic waves.

The "wave number" in kaysers equals the number of wavelengths per centimeter; thus 1 kayser equals 100 per meter (m-1). The unit honors J. H. G. Kayser (1853-1940), who compiled a giant atlas of chemical spectra. The unit is often abbreviated K, although this conflicts with the symbol for the kelvin. kayser (K) (2) a unit of energy used in atomic and molecular physics. Since the frequency of a photon is proportional to the energy it carries, the kayser is also equivalent to an energy of 123.984 micro electronvolt . kbp a symbol for 1000 base pairs, used in biochemistry and genetics. As is well known, DNA has the form of a double helix, with bases on one strand paired with bases on the other strand. Thus the length of a segment or fragment of DNA is measured by the number of base pairs. kBtu a symbol for 1000 British thermal units . This unit of energy equals about 1.055 mega joules (MJ) or 0.2931 kilowatt hour (kWh).

kcmil a symbol for 1000 circular mils , a unit of area equal to about 0.5067 square millimeter commonly used in stating wire gauges. keddah a traditional Egyptian unit of liquid volume also used in other parts of the Middle East. The keddah is equal to about 2.0625 liter (about 2.18 U.S. liquid quarts or 1.815 British Imperial quarts). keel a traditional British unit of weight for coal. After considerable variation, the keel of coal was standardized in 1695 as 21.2 long tons , or 47 488 pounds (21.5402 metric tons). This is the approximate weight of coal carried at that time by barges on the river Tyne in northern England; the barges were also called keels, from the Dutch word kiel for such a ship. keg [1] a traditional unit of volume or quantity, varying with the item contained in the keg. A keg of herring, for example, contains 60 fish. A keg of wine is frequently 12 U.S.

gallons (about 45.42 liters), and a keg of beer is 1/2 barrel or 15.5 U.S. gallons (about 58.67 liters). "Keg" comes from an old Norse word for a small barrel. keg [2] a traditional unit of weight for nails. A keg of nails weighs 100 pounds and thus has a mass of about 45.359 kilograms. kelvin (K) the SI base unit of temperature, previously called the degree Kelvin (°K). One kelvin represents the same temperature difference as one degree Celsius . In 1967 the General Conference on Weights and Measures defined the temperature of the triple point of water (the temperature at which water exists simultaneously in the gaseous, liquid, and solid states) to be exactly 273.16 kelvins. Since this temperature is also equal to 0.01 °C, the temperature in kelvins is always equal to 273.15 plus the temperature in degrees Celsius. The kelvin equals exactly 1.8 degrees Fahrenheit .

The unit is named for the British mathematician and physicist William Thomson (1824-1907), later known as Lord Kelvin after he was named Baron Kelvin of Largs. He is best remembered for his pioneering work on the physics of heat, but he was also a strong advocate of the metric system; his support helped establish the now-familiar electrical units such as the ohm , volt , and farad . ken a traditional Japanese unit of length comparable to the English fathom . The ken equals 6 shaku , which is about 1.818 meters (5.965 feet ). The ken is the length of a traditional tatami mat. At sea, this unit is also called the hiro. kerat a traditional Middle Eastern unit of length, equal to about 9/8 inch or 2.86 centimeters. The unit has the same Arabic root as the carat or karat. key slang for kilo, meaning kilogram. kgm an incorrect symbol for the kilogram (see below). The correct symbol is kg. In engineering, "kgm" is sometimes used to distinguish "kilogram mass" from "kilogram force" (kgf). This practice is not recommended.

kgr another incorrect (but fairly common) symbol for the kilogram. The proper symbol is kg. kgsc a non-standard symbol for kilograms (of force) per square centimeter. kibi- (Ki-) a binary prefix meaning 210 = 1024. This prefix, adopted by the International Electrotechnical Commission in 1998, was supposed to replace kilo- for binary applications in computer science. Thus 1024 bytes of storage is officially a kibibyte, not a kilobyte. However, computer professionals generally dislike this unit (they say it sounds like a cat food) so the ambiguity in the size of a kilobyte persists. The prefix is a contraction of "kilobinary." The symbol Ki-, rather than ki-, was chosen for uniformity with the other binary prefixes (Mi-, Gi-, etc.). kilderkin an old British unit of volume equal to 1/2 barrel or 2 firkins . Based on the current British barrel, this would be 18 (Imperial) gallons , which is about 2.9 cubic feet or 78 liters.

Older kilderkins were generally in the range of 16-18 gallons. The word comes from a Dutch word for a small cask. kilo a common informal name for a kilogram. kilo- (k-) [1] a metric prefix meaning 1000. The prefix is a modification of chilioi, the Greek word for a thousand. kilo- (k-) [2] in measuring the memory of a computer, the prefix kilo- often means 210 = 1024 instead of 1000. By a 1998 resolution of the International Electrotechnical Commission, the new prefix kibi- (Ki-) should replace kilo- for 210. However, this doesn't seem to be happening. kiloampere (kA) a unit of electric current equal to 1000 amperes . kilobar (kbar or kb) a metric unit of pressure, used particularly in industrial applications and in geology for measuring high pressures. The kilobar equals 1000 bars , 100 mega pascals , or about 14 503 pounds per square inch.

(Note: in the investment world a kilobar is a bar of gold, silver, or platinum weighing 1 kilogram.) kilobase (kb) a unit of genetic information equal to the information carried by 1000 pairs of the base units in the double-helix of DNA; also used as a unit of relative distance equal to the length of a strand of DNA containing 1000 base pairs. kilobecquerel (kBq) a unit of radioactivity equal to 1000 atomic disintegrations per second or 27.027 nano curies (nCi). kilobit (kbit or kb) a unit of information equal to 1000 bits, or, in some cases, equal to 1024 bits or 128 bytes . The larger unit is now supposed to be called a kibibit. kilobit per second (kbps, kb/s) a unit of data transmission rate equal to 1000 bits per second. The symbol kb/s is preferable to kbps for this unit. kilobyte (kB) a unit of information equal to 1000 bytes.

As a unit of computer storage, however, the kilobyte is usually equal to 1024 bytes, although this should now be called a kibibyte. kilocalorie (kcal) an ambiguous metric unit of energy. The ambiguity arises because there are two "calories" in common use, identified in this dictionary as the calorie (the small or gram calorie equal to 4.1868 kilo joules ) and the Calorie (the large or kilogram calorie equal to 4.1868 megajoules). The term kilocalorie properly means 1000 calories, which is the same as 1 Calorie. In other words, "kilocalorie" is the correct name for the unit known in nutrition simply as the "calorie." kilocurie (kCi) a unit of radioactivity equal to 1000 curies or 37 tera becquerels (TBq), that is, 37 trillion atomic disintegrations per second. The strength of the powerful radiation sources used in cancer therapy are customarily stated in kilocuries.

kilocycle (kc) 1000 cycles; a term sometimes used as an informal name for the kilohertz. kilocycle per second (kc/s) an older name for the kilohertz. kilodalton (kDa) a unit of mass equal to 1000 atomic mass units . See dalton . kiloelectronvolt (keV) a unit of work or energy used in physics, equal to 1000 electronvolts . kilofoot (kft) a traditional unit of distance equal to 1000 feet or exactly 304.8 meters. This odd combination of a metric prefix and an English unit is used in telecommunications to describe cable lengths and transmission distances. kilogauss (kGs) a metric unit of magnetic flux density equal to 1000 gauss or 0.1 tesla . The strength of industrial magnets and solenoids is often expressed in kilogauss, although this unit is being replaced gradually by the tesla. kilogram (kg) [1] the base unit of mass in the SI and MKS versions of the metric system.

The kilogram was originally defined to be the mass of one cubic decimeter of pure water, but to provide precise standards it was necessary to construct physical objects of specified mass. Therefore, the kilogram is defined as the mass of the standard kilogram, a platinum-iridium cylinder in the custody of the International Bureau of Weights and Measures (BIPM) near Paris, France. Copies of this bar are kept by the standards agencies of all the major industrial nations, including the U.S. National Institute of Standards and Technology (NIST). BIPM supports efforts to redefine the kilogram in a way that does not refer to a specific object, and this may become possible in the near future. One kilogram equals exactly 1000 grams , or about 2.204 622 6 pounds. kilogram (kg) [2] a unit of force; see below under kilogram force. kilogram calorie (kcal or kgcal) the "large calorie" or "food calorie" used in nutrition, equal to 1000 ordinary ("gram") calories . The correct name for this unit is kilocalorie.

kilogram force (kgf) a unit of force equal to the gravitational force on a mass of one kilogram. One kilogram of force equals 9.806 65 newtons , or 2.204 622 6 pounds of force in the traditional English system. Using this unit revives the old confusion between mass and weight, one of the worst features of traditional measurement systems, so it is really a very bad idea. However, kilograms of force have been used rather frequently in engineering and physics. This unit is also called the kilopond. kilogram meter (kgf·m or kg·m) [1] a metric unit of work or energy equal to 9.806 65 joules (J). This is the work done by one kilogram of force (see below) acting through a distance of one meter. kilogram meter (kgf·m or kg·m) [2] a metric unit of torque equal to 9.806 65 newton meters (N·m).

kilogram mole, kilogram molecule, kilogram molecular weight (kgmol or kgmole) various older names for a unit of the amount of a chemical compound. One kilogram mole of a compound is the number of kilograms of the compound equal to the molecular weight of a molecule of that compound measured in atomic mass units . The correct name for this unit is the kilo mole (kmol). kilogram (force) per square centimeter (kgf/cm2 or kg/cm2 or kgsc) a common metric unit of pressure equal to 98.0665 kilopascals (see below) or about 14.2234 pounds per square inch (lbf/in2 or psi). Similarly, one kilogram force per square meter is equal to 9.806 65 pascals . kilogram weight (kgf) a kilogram force (see above). kilohertz (kHz) a common unit of frequency equal to 1000 per second or 1 per millisecond. AM radio stations have signal frequencies measured in kilohertz. kilojoule (kJ) a common metric unit of work or energy, comparable to the British thermal unit ( Btu ).

In fact, one kilojoule equals approximately 0.947 817 Btu. In other energy units, the kilojoule is also equivalent to 0.238 846 kilo calories , 0.277 778 watt hour, or 737.562 foot-pounds in the traditional English system. kilokibibyte a unit of computer memory equal to exactly 1 024 000 bytes. Storage on floppy disks is traditionally stated in multiples of this unit, which has usually been called a "megabyte." But a megabyte should be 1 000 000 bytes, or with a binary understanding it should be 220 = 1 048 576 bytes, and this unit doesn't fit either convention. kiloline a metric unit of magnetic flux, equal to 1000 lines [2] or 10 micro webers . kiloliter (kl or kL) a metric unit of volume.

The kiloliter is identical to the cubic meter: it equals about 35.3147 ft3, 1.307 95 yd3, 264.17 U.S. gallons, 219.99 British Imperial gallons, 7.497 U.S. bushels, or 6.049 British Imperial bushels. kilomega- (kM-) an obsolete metric prefix denoting 109 (1 U.S. billion). This prefix has been replaced by giga- (G-). kilometer (km) a common metric unit of length or distance. One kilometer equals exactly 1000 meters, about 0.621 371 19 mile , 1093.6133 yards , or 3280.8399 feet . Oddly, higher multiples of the meter are rarely used; even the distances to the farthest galaxies are usually measured in kilometers.

The unit is sometimes pronounced with the accent on the first syllable (similar to the pronunciation of other metric units using kilo-) and sometimes on the second (helping to distinguish it from other metric units using kilo-). Both pronunciations are acceptable; there are no official pronunciations for SI units. kilometer per hour (km/h) a common metric unit of speed or velocity. 1 km/h is equal to 5/18 meter per second, 0.621 371 19 miles per hour or 0.911 344 42 feet per second. The only correct symbol for this unit is km/h; variations such as kmph or kph should not be used. kilometer per liter (km/L or km/l) a fairly common unit of fuel consumption rate for vehicles. Outside the U.S., the official measurement of fuel efficiency is usually liters per 100 kilometers, but many people prefer to express the measurement in kilometers per liter. One kilometer per liter is equal to about 2.352 146 miles per U.S. gallon or 2.824 809 miles per Imperial gallon.

A consumption rate of x kilometers per liter is equivalent to 100/x liters per 100 kilometers. kilomole (kmol) a unit of amount of substance equal to 1000 moles . One kilomole of a compound is the number of kilograms of the compound equal to the molecular weight of a molecule of that compound in atomic mass units . The kilomole was formerly called the kilogram mole. kilonewton (kN) a common metric unit of force, the kilonewton equals 1000 newtons ; it is a force that will accelerate a mass of 1 metric ton at the rate of 1 meter per second per second. One kilonewton equals 101.972 kilograms of force, 224.809 pounds of force or 7233.01 poundals . kilohm or kiloohm a unit of electric resistance equal to 1000 ohms . The simplified spelling kilohm is approved by the Institute of Electrical and Electronics Engineers (IEEE).

kilo-oersted (kOe) a CGS unit of magnetic field strength equivalent in MKS units to 79 577.472 ampere-turns per meter. The unit, used for stating the field strengths of industrial magnets, is almost always spelled with the hyphen. kiloparsec (kpc) a unit of distance used in astronomy, the kiloparsec equals 1000 parsecs , 3261.631 light years , 3.085 678 x 1016 kilometers, or about 19.18 quadrillion miles. The Solar System is located about 8 kiloparsecs from the center of the Milky Way galaxy. kilopascal (kPa) a common metric unit of pressure.

One kilopascal equals 1000 pascals (Pa), 10 millibars (mb), or about 0.145 038 pounds per square inch (lbf/in2 or psi), 20.8855 pounds per square foot, 7.502 millimeters of mercury (mm Hg), 0.2953 inches of mercury (in Hg), 4.015 inches of water column (in WC), or 0.3346 foot of head (ft hd). kilopond (kp) another name for the kilogram of force (kgf) (see above). kilorad (krad) a common unit of radiation dose equal to 1000 rads, 10 grays , or 10 joules of energy per kilogram of mass. kilosecond (ks or ksec) a unit of time equal to 1000 seconds (16 minutes 40 seconds). Although it is never used in ordinary life, the kilosecond has many uses in science. One day is equal to 86.4 kiloseconds.

kiloton (kt or KT or kton) [1] an ambiguous unit of mass, ambiguous because it may refer to 1000 U.S. tons (907 185 kilograms), 1000 British tons (1 016 047 kilograms), or 1000 metric tons (1 million kilograms, or 1 gigagram). To reduce this confusion, the metric unit should be written kilotonne. kiloton (kt or KT or kton) [2] a unit of explosive energy equal to 1012 thermochemical calories (or one teracalorie). This is approximately the energy released by exploding 1000 U.S. tons (2 million pounds) of TNT. The kiloton is equal to exactly 4.184 terajoules (4.184 x 1012 joules ) or about 4 billion Btu . kilovolt (kV) a common unit of electric potential equal to 1000 volts . Electric distribution lines operate at potentials of anywhere from several to several hundred kilovolts.

kilovolt ampere (kV·A) a common unit of load in power engineering, equal to 1000 volt amperes . kilowatt (kW) a common metric unit of power, equivalent to 1000 watts , about 1.341 022 horsepower , or 737.562 foot-pounds per second. kilowatt hour (kW·h or KWH or kw hr) a commercial unit of electric energy. One kilowatt hour represents the amount of energy delivered at a rate of 1000 watts over a period of one hour. Since the watt is 1 joule /sec and there are 3600 seconds in an hour, the kilowatt hour is equivalent to exactly 3.6 megajoules of energy, or about 3412.141 Btu , 859.846 (kilogram) Calories , or about 2.655 million foot pounds. kilowatt year (kW·yr) a commercial unit of electric energy.

One kilowatt year represents the amount of energy delivered at a rate of 1000 watts over a period of one year. This equals 8760 kilowatt hours for an ordinary (365 day) year or 8784 kilowatt hours for a leap year. For greater accuracy, it's best to use 365.25 days per year; with this definition, the kilowatt year is exactly 8766 kilowatt hours or 31.5576 gigajoules; this is about 29.911 million Btu or 23.273 billion foot-pounds. kiloyard (kyd) a traditional unit of distance equal to 1000 yards (exactly 914.4 meters). This unit is used in the U.S., British, and Commonwealth navies in describing ship distances and target ranges. kiloyear (kyr) a unit of time equal to 1000 years, commonly used in archaeology, paleontology, climatology, and related sciences. Of course, a kiloyear is the same as a millennium.

kin the Japanese version of the catty , a common weight unit of the Far East. The Japanese identified this unit with a traditional unit equal to about 1.323 pounds or almost exactly 600 grams; this is about 0.75% smaller than the Chinese catty. kip [1] an informal unit of force, sometimes used by engineers to express the amount of weight borne by a structure. One kip equals 1000 pounds (453.59 kilograms) of force or about 4.4482 kilo newtons . The name of the unit is an abbreviation of "kilopound." kip [2] a symbol for 1000 inch pounds, used as a unit of energy or torque. In this usage one kip is equal to 83.333 foot pounds (lbf·ft), 112.985 joules (J), or, for torque, 112.985 newton meters (N·m). kip [3] an old English word for a bundle of hides. It was sometimes used as a unit of quantity, usually equal to 50.

klafter [1] a traditional unit of distance in German-speaking countries, comparable to the English fathom . The Austrian klafter is equal to 1.8965 meters (6.22 feet). In Switzerland the klafter was brought into the metric system at exactly 1.8 meters (5.9055 feet). This unit is also called the faden. klafter [2] a traditional German unit of volume for stacked firewood, comparable to the English cord. A klafter of wood was generally 1 klafter tall and 1 klafter long, but there was less agreement on its width, that is, the length of the logs. A common width was 3 fuss or 0.5 klafter, making the volume about 3.41 steres (cubic meters) or 0.941 cord by the Viennese definition, 3.34 steres or 0.921 cord in northern Germany. klick, klik a common but incorrect symbol for kilometers per hour. The correct symbol is km/h. kMT a symbol for 1000 metric tons or 1 kilotonne, commonly used in the mining industry.

(The proper symbol for this unit is kt.) km/t a symbol for "kilometer per time," used on road signs in Scandinavia, especially Norway, for kilometers per hour. Knoop hardness (HK or KHN) a measure of the hardness of a metal introduced by Knoop in 1939. The Knoop test is similar to the Vickers test in that a diamond penetrator is used to indent the sample being tested, but it uses a rhombohedral diamond rather than a pyramidal diamond point. It is similar to the Rockwell test in that the hardness measure is the depth of the penetration rather than its area. The result is measured in kilograms of force per square millimeter but should be stated as an empirical measurement, without units. knot (kn or kt) [1] a unit of velocity equal to one nautical mile per hour. Knots are customarily used to express speeds at sea, including the speed of the ship as well as the speeds of the wind and of the current. The word comes from the former method of measuring a ship's speed, which involved use of a knotted cord called the log line.

One knot equals about 1.1508 miles per hour, exactly 1.852 kilometers per hour, or 0.5143 meters per second. Since kt is the established symbol for the kilotonne, kn is the best choice as a symbol for the knot. knot [2] an informal unit of distance equal to the nautical mile . köddi a traditional Arabic unit of volume, equal to about 4/3 British Imperial gallon or 7.58 liters. koku a traditional Japanese unit of volume, equal to about 180.391 liters (39.68 British Imperial gallons or 6.37 cubic feet). The unit originated as an estimate of the amount of rice needed to feed a person for a year. kommerzlast German for "commercial load," now interpreted as a metric unit equal to exactly 3 tonnes (about 6613.9 pounds). kon Korean name for the catty . koyan a Far Eastern unit of weight equal to 4000 catty or 5333.33 pounds (8/3 short ton ). kph a common but incorrect symbol for kilometers per hour.

The correct symbol is km/h. krina a traditional unit of volume in Bulgaria, now expressed in the metric system as being equal to exactly 20 liters (4.40 British Imperial gallons or 5.28 U.S. liquid gallons). Krügerl or Krügel a common unit of volume for beer in Austria, equal to 1/2 liter. The name of the unit is related to Krug, a jug or tankard. ksf, ksi symbol for kips (kilopounds) per square foot or per square inch, traditional engineering units of pressure or stress. 1 ksf = 47.880 257 kilo pascals (kPa) and 1 ksi = 6.894 757 megapascals (MPa). These units are often used to express the strength of materials (meaning the maximum pressure the material can resist). ksym/s a unit of radio transmission rate equal to 1000 symbols per second. kulmet a traditional Latvian unit of volume equal to about 10.93 liters (2.40 British Imperial gallons or 2.89 U.S. liquid gallons).

A similar Estonian unit, the külimet, equals about 11.48 liters (2.53 British Imperial gallons or 3.03 U.S. liquid gallons). kunitz or Kunitz unit a unit used in biochemistry to describe the concentration or activity of the enzyme ribonuclease, which attacks ribonucleic acid (RNA). The action of the enzyme causes an increase in the absorbance of ultraviolet light. One kunitz is the concentration of the enzyme causing an increase in absorbance at a wavelength of 260 nm by 0.001 per mL of enzyme when acting upon highly polymerized DNA at 25 C and pH 5.0 under specified conditions. The unit's name recognizes the Russian-American biochemist M. Kunitz, who proposed the standard test in 1946. kvadrat- Scandinavian prefix meaning "square." In particular, a kvadratmeter is a square meter. The prefix is common to Danish, Norwegian, and Swedish. kwan a traditional Japanese unit of weight equal to 6.25 kin (see above), which is about 8.27 pounds or 3.75 kilograms.

kya a common abbreviation (in English speaking countries) for "thousand years ago." The "k" is the metric symbol for kilo- (1000). kyu a metric unit of distance used in typography and graphic design. The kyu, originally written Q, is equal to exactly 0.25 millimeter, about 0.71 point [2], or about 14.173 twips . The spelling "kyu" seems to have been introduced by the software company Macromedia. Kz How to Find The Purity of Gold and Silver Jewelry How to Find The Purity of Gold, Silver and Platinum For Gold Jewelry made in the United States or Canada it should be stamped 14K, 18K, 22K or some number greater then 9 and less then 24 with a "K" or "kt" after it. Since 10K is the minimum purity in the U.S. that an item can be sold as "Gold" and 24K is rarely used for making jewelry. The "K" stands for Karat. A Karat is a measure of gold purity.

This is sometimes confused with Carat, which is a unit of weight used for diamonds and other gemstones that is equal to 200 milligrams. 1 Karat equals 1/24 of the whole. An alloy made of 14 parts pure gold and 10 parts of copper or some other metal is known as 14K or 14 Karat gold...18 parts pure gold and 6 parts of another metal, is 18K or 18 Karat Gold. Outside of the U.S. and Canada, the spelling "Carat" is commonly used instead of "Karat" to describe gold purity. You will find the abbreviation "ct." being used and 14ct, 18ct or 9ct...

as a purity stamp instead of 14K, 18K or 9K....( It is only in this context, that the words "Carat" and "Karat" describe the same thing, 1/24 part or 1/24 of the whole.) In Europe, the Parts Per Thousand format is usually stamped to indicate an items gold purity, " .375 " for gold that is 37.5% pure, " .417 " for gold that is 41.7% pure (10K in the U.S.), " .585 " for gold that is 58.5% pure (14K or 58.3% in the U.S.) , " .750 " for gold that is 75% pure (18K in the U.S.). For Sterling Silver it should be stamped " Sterling "," Ster ", ".925 " or have a symbol or mark that indicates that it is Sterling Silver and not silver plated or stainless steel. The standard or law for which an item can be sold as "sterling silver" is it must contain 92.5% pure silver.

There are some resources on the internet to help you find sterling silver hallmarks from silversmith's all over the world. For Silver, Platinum or Palladium Jewelryit is usually stamped .800, .950, .830, .900 or something in a .000 format. This format is simply expressing the items purity as Parts Per Thousand. If your item is genuine and marked .800 it is 80% pure. If it's marked .950 it's 95% pure. If it's marked .835 it's 83.5% pure precious metal. Platinum jewelry is usually stamped with a "Pt" or "Plat" after the purity.. ..ie, ".950 Pt" or ".950 Plat", "900 Pt" or "900 Plat". Purity Stamps and Hallmarks: Most all contemporary precious metal goods are by law, stamped to indicate their purity. If your item is unmarked, it may mean that it has been "electroplated" or that it may not be made from precious metal at all, so you will have to do a little more research.

Possibly purchase a test kit or take it to a reputable jeweler for a purity test if you are unsure. Electroplated Goods: If the item is stamped "EPNS" or "EPBM" this indicates that it has been electroplated. When an item has been electroplated, it means that it only has a thin coating of precious metal instead of being a true alloy where the metals are mixed together at melting point temperatures. It is also worth noting that electroplated items are VERY common and basically worthless from a precious metal perspective. They do not contain enough gold or silver to merit refining. The calculators are NOT intended to work with anything that has only been "Electroplated" with precious metal. How to Test Gold Jewelry for Purity Advertisement How Gold Purity Is Measured Perhaps you’ve heard of karat (abbreviated K or kt), which is the most widely used measure of gold purity. Karat is measured on a scale from 0 to 24. To see how much gold your jewelry contains, look at the stamp indicating its karat. Thus, a piece of jewelry that has a purity of one karat consists of 1 part gold and 23 parts other metals or alloys.

Purity can also be measured in percentages and parts per thousand. To convert karats to percentage, divide the karat number by 24 and multiply the result by 100. For instance, to figure out the gold percentage in your 20-karat ring, divide 20 by 24, thus obtaining 0.833, or 83.3% gold content (which also translates to 833 parts per thousand). How to Find Out the Gold Content of Your Jewelry To see how much gold your jewelry contains, it is usually enough to look at the piece and find the stamp indicating its karat. (Text continues below ad section.) Sponsored Links Advertisement For instance, if you see a marking “10kt”, this means that your piece contains 10 parts gold and 14 parts other metals; this karat value also translates to 41.7% gold content. Sometimes, you will not see purity measured in karats but rather in parts per thousand (especially common in Europe). If that’s the case, you will see a 3-digit number stamped on your jewelry.

For example, if you see the mark “583”, this means that the gold content is 583 parts per thousand. Divide that by 10 and you will get the percentage value of gold content, or 58.3%. To find the purity of the same piece in karats, divide 583 by 1000 and multiply the result by 24 – the result is 14 karats. Click here to see a collection of the latest and most popular gold jewelry . Karat Values and Their Percentage Equivalents Here are the most widely used karat marks and their corresponding percentages (in brackets you can see the respective parts-per-thousand values): 24K – 99.9% (999) 10K – 41.7% (417) What Does It Mean If My Jewelry Has “KP” (or “P”) Stamped? If you come across jewelry marked “KP”, you should know that the “P” stands for “plumb”. This marking means that the piece is guaranteed to have at least the karat value indicated.

For example, if a ring is marked 20KP, it has a gold purity of no less than 20 karats. But why was this additional marking introduced if the karat number itself is supposed to indicate purity? The reason has something to do with gold sellers, who are allowed to put a karat number that can differ slightly from the actual gold content of the merchandise. In the U.S., the permitted deviation is no more than 0.5 karats. So, a ring that is actually 21.5K may be stamped with a 22K mark. However, if the ring has the letter “P” after the karat symbol, you can assume that the gold purity is at least what the number indicates. What If I Can’t See Any Marks? Sometimes, there will be no marks stamped on your jewelry. In such cases, the most accurate assessment of gold purity can be made by a professional. Usually, jewelers use nitric acid to find out the real karat of a piece. So, if you have unmarked gold and want its purity evaluated, you can always go to a jewelry store and ask to have your jewelry tested.

How is Gold Checked for Purity | How to Check Gold How is Gold Checked for Purity? By Joseph Castro, Live Science Contributor | April 30, 2013 04:28pm ET MORE The tyrannosaur of the minerals, this gold nugget in quartz weighs more than 70 ounces (2 kilograms). Credit: Heritage Auctions The value of gold is based on the karat system, which is a 24-point scale signifying the percentage of gold a piece of metal contains. So, if gold jewelry is 14K, it is 14 out of 24 parts gold, or 58.33 percent gold. The acid test is the cheapest method used to check gold . Simple acid test kits typically come with a black touchstone and several acid solutions, which are marked for different karats. Experts start by scratching the touchstone using the gold that needs to be tested, leaving a streak on the stone. If the questionable gold is purportedly 14K, they will then make a parallel control streak using a piece of gold that is already known to be 14K.

Finally, they'll put a drop of the acid solution on both streaks and compare the ensuing chemical reactions. Jewelers may also use electronic gold testers to figure out the quality of a piece of gold. Using a specific liquid or gel, they first create a circuit between the device's probe and the gold. The device then tests the gold's electrical conductivity — this property not only tells the jeweler if the material is actually gold, but also its purity. Electronic gold testers are fairly accurate when used properly (they must be fully cleaned of the gel in between uses). The most accurate tests use X-ray fluorescence spectrometers (XRF). These machines, which can cost thousands of dollars, send X-rays through the tested item. The material's atoms become momentarily excited and move into a higher energy state; when they return to their ground state, they release radiation, which the XRF detects and reads. By analyzing the radiation, the machine figures out exactly what the item is made of. Follow LiveScience on Twitter @livescience . We're also on Facebook & Google+ . Editor's Recommendations What is gold karat? - Gold Price OZ What is gold karat?

Karat - The unit of purity for gold Menu☰ What is gold karat? - Gold Price What is gold karat? When people buy gold jewelry in the store, the seller often describes it in terms of karats (abbreviated kt or K). The gold jewelries are made with different karat, such as 10 karat, 12 karat, 14 karat, and 18 karat. High karat gold jewelries are more expensive. Well, what exactly does the "karat" mean? What is the karat? Karat is a unit of purity for gold alloys, rather than weight. The word "karat" is from the carob seed, which was used as balance scales to measure the weight of gold in ancient Asian bazaars. What is Gold Karat? Since the pure gold is too soft to make exquisite jewelries. Therefore, the gold jewelries are almost alloy which are mixed with other metals, such as silver, copper, or zinc. Pure gold is 24 karats. A unit karat of gold is equal to 1/24 part (4.1667%).

The gold karat shows how many parts of gold and how many parts of other metals in a gold jewelry. The following chart shows the differences between the different karats, and also shows the percentage of gold and other metals. Karats gold 25% other metal 75% As I mentioned, gold is a relatively soft metal, so high-karat stuff are often easily damaged. A 24 karat item is generally reserved for display or ceremonial use. In the stores, most gold items have a karat rating in the range 9 to 18. In the US, the minimum karat value for gold jewelry to be sold is 10, but in the UK 9 karat is more common. In additional, gold purity does not affect its weight! Different color of gold are mixed with different other metals. For example, gold mixes copper is called red karat gold. What's the difference between Karat and Carat? We are often confusion over the differing use of "carat" and "karat". The Karat is a gold unit for purity, and Carat is a unit for mass which is used for measuring the weight of gemstones and pearls (1 carat is equal to 200mg).

However, carat and karat are usually used interchangeably in some countries. How to test the purity of gold? There are two common methods to test gold for its purity, Acid Test Kits and Electronic Testing Kits. However, any acid testing will lose some small amount of gold. Miscellaneous Units of Measure Math > Measurement Miscellaneous Units of Measure Below is information about units of measure, including acre, bolt, gross, hertz, knot, light-year, parsec, pi, ream, sound, square, stone, and more. 93,000,000 miles, the average distance of the earth from the sun. Used for astronomy. bale A large bundle of goods. In the U.S., the approximate weight of a bale of cotton is 500 pounds. The weight varies in other countries. board foot (fbm) 144 cubic inches (12 in. × 12 in. × 1 in.). Used for lumber. bolt British thermal unit. Amount of heat needed to increase the temperature of one pound of water by one degree Fahrenheit (252 calories). carat (c) 200 milligrams or 3.086 grains troy.

Originally the weight of a seed of the carob tree in the Mediterranean region. Used for weighing precious stones. chain (ch) A chain 66 feet or one-tenth of a furlong in length, divided into 100 parts called links. One mile is equal to 80 chains. Used in surveying and sometimes called Gunter's or Surveyor's chain. cubit Unit of relative loudness. One decibel is the smallest amount of change detectable by the human ear. ell, English 11/4 yards or 1/32 bolt. Used for measuring cloth. freight, ton (also called measurement ton) 40 cubic feet of merchandise. Used for cargo freight. great gross 12 dozen or 144. hand 4 inches or 10.16 cm. Derived from the width of the hand. Used for measuring the height of horses at withers. Modern unit for measurement of electromagnetic wave frequencies (equivalent to “cycles per second”). hogshead (hhd) The power needed to lift 33,000 pounds a distance of one foot in one minute (about 11/2 times the power an average horse can exert).

Used for measuring power of steam engines, etc. karat (kt) A measure of the purity of gold, indicating how many parts out of 24 are pure. For example: 18-karat gold is 3/4 pure. Sometimes spelled carat. knot Not a distance, but the rate of speed of one nautical mile per hour. Used for measuring speed of ships. league light-year 5,880,000,000,000 miles, the distance light travels in a vacuum in a year at the rate of 186,281.7 miles (299,792 kilometers) per second. (If an astronomical unit were represented by one inch, a light-year would be represented by about one mile.) Used for measurements in interstellar space. magnum parsec Approximately 3.26 light-years or 3.08 × 1013 km (1.92 × 1013 mi).

Term is combination of first syllables of parallax and second, and distance is that of imaginary star when lines drawn from it to both Earth and the Sun form a maximum angle or parallax of one second (1/3600 degree). Used for measuring interstellar distances. pi (π) 3.14159265+. The ratio of the circumference of a circle to its diameter. For practical purposes, the value is used to four decimal places: 3.1416. pica 1/6 inch or 12 points. Used in printing for measuring column width, etc. pipe 2 hogsheads. Used for measuring wine and other liquids. point .013837 (approximately 1/72) inch or 1/12 pica. Used in printing for measuring type size. quintal 100,000 grams or 220.46 pounds avoirdupois. quire Used for measuring paper. Sometimes 24 sheets but more often 25. There are 20 quires to a ream. ream Used for measuring paper.

Sometimes 480 sheets, but more often 500 sheets. roentgen International Unit of radiation exposure produced by X-rays. score 20 units. sound, speed of Usually placed at 1,088 ft. per second at 32°F at sea level. It varies at other temperatures and in different media. span 9 inches or 22.86 cm. Derived from the distance between the end of the thumb and the end of the little finger when both are outstretched. square 100 square feet. Used in building. stone Legally 14 pounds avoirdupois in the U.K. therm 100,000 Btus. township U.S. land measurement of almost 36 square miles. The south border is 6 miles long. The east and west borders, also 6 miles long, follow the meridians, making the north border slightly less than 6 miles long. Used in surveying. tun Precious Metals:Data & Statistics How is Gold Purity Measured? The purity of gold articles is generally described in three ways. You may find percentage or fineness marks on certain jewelry, particularly from foreign manufacturers.

Here's how to translate those marks into something meaningful for customers who understand only karats. Copyright © 1998 by Bond Communications.

Question: What unit is used to measure the purity of gold?
Answer: Carat