mm long when they hatch, and when they hatch they have dark bands which go around their bodies.These bands lighten as the babies grow into adults which have spots instead of bands. Leopard geckos are normally lavender or yellow in colour, but pet leopard geckos come in different "colour morphs" like albino, "Banana blizzard", "Blizzard", "Ghost", "High Yellow", "Hyper Xanthic", "Jungle", "Leucistic", "Normal" or "Wild", "Patternless", "Red-stripe", "Snow", "Tremper Albino" and many more.
Like many lizards, the leopard gecko has a tail that breaks off when grabbed by a predator. The tail breaks at a crack in the vertebra, and the surrounding muscles are arranged so that they separate neatly and instantly. A muscle closes around the artery in the tail at the point of the break and stops blood loss. Normally a new tail grows back. This method helps the leopard gecko to escape when attacked.
The leopard gecko is found in dry rocky regions, dry grasslands and deserts of southern Central Asia, Afghanistan, Pakistan, northwest India, and parts of Iran.
The temperatures of these areas during winter can be quite low, below , forcing the animals underground into semi-hibernation, called "brumation", and they live on fat reserves. Leopard geckos are crepuscular reptiles; during the day they hide in burrows, but they are active at dawn and dusk when the temperature is favorable.
Leopard Geckos are friendly, docile creatures by nature, but they sometimes bite. If held in a human hand they will only bite if they mistake a finger for food, or if the person is holding the gecko too tightly.
In the wild, leopard geckos feed mainly on insects, fruits, spiders, snails, small lizards, birds, and bird eggs. In captivity they feed on mealworms, crickets, and sometimes baby mice.
Leopard geckos reach sexual maturity at the age of one to three years. Mating usually happens during the rainy season. During courtship, the male walks alongside the female, licking and lightly biting her side. He then grasps her neck in his mouth. If she accepts to mate with him, she lifts her tail allowing the male to insert one of his paired copulatory organs, called hemipenes. Female leopard geckos can store sperm in their reproductive tracts for 15 months or more. They can lay up to five clutches of one or (usually) two eggs during the five month breeding season, and may use some of the stored sperm to fertilize each clutch. The eggs hatch after around 55 days.
There are five subspecies of the Leopard gecko:
Pitchblende
Pitchblende is a radioactive, uranium-rich mineral and ore. It has a chemical composition that is largely UO, but also contains UO and oxides of lead, thorium, and rare earth elements. It is known as pitchblende due to its black color and high density. It is also commonly referred to as Uraninite. The mineral has been known at least since the 15th century from silver mines in the Ore Mountains, on the German/Czech border. Pitchblende found in Germany was used by M. Klaproth in 1789 to discover the element uranium.
Pitchblende contains a small amount of radium as a radioactive decay product of uranium. Because the uranium isotopes U and U will decay to form the lead isotopes Pb and Pb, pitchblende also always contains small amounts of lead. Small amounts of helium are also present in pitchblend as a result of alpha decay. Helium was first found on Earth in pitchblende after having been discovered in the Sun's atmosphere.
Pitchblende is a major ore of uranium. Some of the highest grade uranium ores in the world were found in the Shinkolobwe mine in the Democratic Republic of the Congo (the initial source for the Manhattan Project) and in the Athabasca Basin in northern Canada. Another important source of pitchblende is at Great Bear Lake in the Northwest Territories of Canada, where it is found in large quantities associated with silver. It also occurs in Australia, Germany, England, and South Africa. In the United States it can be found in the states of New Hampshire, Connecticut, North Carolina, Wyoming, Colorado, Arizona and New Mexico.
Uranium ore is generally processed close to the mine into yellowcake, which is an intermediate step in the processing of uranium.
Rare earth element
Rare earth elements ("REEs") are a set of seventeen chemical elements. They include the fifteen lanthanides plus scandium and yttrium. Scandium and yttrium are rare earth elements since they are often found in the same ore deposits as the lanthanides and have similar chemical properties.
Although they are called rare, rare earth elements are not extremely rare on Earth. They were called this because they are spread very evenly over the Earth, so it is hard to find a lot in one place. Promethium is rare, because it is radioactive, and decays.
Cerium, one of the lanthanides, is the 25th most common element in the Earth's crust. However, most rare earth elements are not found concentrated or in pure forms.
A table listing the seventeen rare earth elements, their atomic number and symbol, the origin of their names, and some of their uses is provided here. Some of the rare earths are named after the scientists who discovered them, and some are named based on where they were discovered.
Rare earth elements are heavier than iron. They are made by supernovae (exploding stars). In nature, fission of uranium-238 creates very small amounts of radioactive promethium. Most promethium is synthetically created in nuclear reactors.
Rare earth elements change through time in small quantities (ppm, parts per million). Their proportion can be used for geologic dating and dating fossils.
The rare earth elements are often found together. The longest-lived isotope of promethium has a half life of 17.7 years. Because of this, the element exists in nature in only very small amounts. Promethium is one of the two elements that do not have stable (non-radioactive) isotopes and are followed by stable elements (the other being technetium).
Because all lanthanides are close in size, the rare earth elements have always been hard to separate. Even with eons of geological time, separation of the lanthanides in nature has only rarely gone farther than the separation between light versus heavy lanthanides, otherwise known as the cerium and yttrium earths. This geochemical separation is shown in the first two rare earths that were discovered. These were yttria in 1794 and ceria in 1803. When first found, each was a mixture of all of the rare earths. Large ore bodies of the cerium earths can be found around the world and are being exploited. Ore bodies for yttrium are rarer. Also, they are usually smaller and less concentrated.
Until 1948, most of the world's rare earths came from sand deposits in India and Brazil. Through the 1950s, South Africa mined most of the world's rare earths. This happened after large veins of a rare earth bearing mineral were found there. Through the 1960s until the 1980s, a mine in California was the leading producer. Today, the Indian and South African deposits still make some rare earth concentrates, but they are very small compared to the amount being produced in China. China had produced over 95% of the world's rare earth supply. Most of this has been done in Inner Mongolia, even though it had only 37% of proven reserves. Although these numbers have since been said to have lowered to 90% of global production and a proven reserve rate of only 23% by 2012. All of the world's heavy rare earths (such as dysprosium) come from Chinese rare earth sources such as the polymetallic Bayan Obo deposit. In 2010, the United States Geological Survey (USGS) released a study which found that the United States had 13 million metric tons of rare earth elements.