nyuuzyou/wikis huggingface dataset:
Vinylidene chloride

== Description ==
Colorless liquid that self-polymerizes to form polyvinylidene chloride. Polyvinylidene chloride is used to make saran fibers and food wrapping film.
== Synonyms and Related Terms ==
1,1-dichloroethene; 1,1-dichloroethylene; DCE
== Risks ==
* Toxic by inhalation. 
* Skin contact causes irritation. 
* Extremely flammable. Flash point = 5.6 C. 
* Explosive limits in air 5.6-11.4%. 
* ThermoFisher: SDS
==Physical and Chemical Properties==
Soluble in organic solvents. Insoluble in water.
Composition 	CH2:CCl2
CAS 	75-35-4
Melting Point 	-122.53 C
Density 	1.2129 g/ml
Molecular Weight	mol. wt. = 97.0
Refractive Index	1.4249
Boiling Point 	31.77 C
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: refractive index= 1.61
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
* The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 10134 (refr index = 1.4249)
* Wikipedia: http://en.wikipedia.org/wiki/Vinylidene_chloride (Accessed Mar. 20, 2006)
Category:Materials database
Vinylite

== Description ==
[Bakelite, Union Carbide] A former trademark for polyvinyl acetate resins currently sold under the trademarks of AYAC, AYAB, AYAA, AYAF, and AYAT.
== Synonyms and Related Terms ==
Vinylite A; Vinylite 0200; Vinylite VYHH
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 847
Category:Materials database
Vinyon fiber

== Description ==
A generic name for a manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of vinyl chloride units (Federal Trade Commission definition). Originally, Vinyon was a trademark of Union Carbide for polyvinyl chloride fibers copolymerized with acrylonitrile called Vinyon N. Soon other variations of PVC polymers and copolymers called Vinyon were developed. By the 1950s, FTC adopted the name vinyon as a general term for PVC fibers. Vinyon fibers have good resistance to chemicals, bacteria, and insects. They soften at low temperatures and are often used to bond other fibers into nonwoven fabrics and to make heat sealable paper. They are used as flame-resistant fibers in children's clothing, blankets, draperies, and carpeting. Vinyon fibers are also used in fishing nets, twines, felts, and industrial fabrics such as tarps, awnings, and outdoor furniture.
== Synonyms and Related Terms ==
vinyon fibre; poly(vinyl chloride) fiber; polyvinyl chloride; chlorofiber; Fibravyl [Rhone-Poulenc Textile, France]; Retractyl; Rhovyl®; Thermovyl®; Leavin [ACSA, Italy]; Clevyl®; Teviron [Japan]; Valren; Viclon [Japan]; Movil [Societa Polymer, Italy]; Vinyon HH [Avtex]; Volpex®
== Risks ==
* Degrades with heat and light to produce hydrochloric acid. 
* May also form carbon monoxide or phosgene.
== Physical and Chemical Properties ==
* Soluble in chlorinated hydrocarbons and aromatic solvents
* Insoluble in water, alcohols, concentrated acids and alkalis
* Burns with green flame and evolves HCl
* Cross section is irregular: polygonal, round or dogbone
* Tenacity = 0.7-3.0 g/denier 
* Elongation 12-125 % 
* Moisture regain =
* Melting Point = 52 C (softens)
* Density = 1.38-1.43 g/ml
== Comparisons ==
== Resources and Citations ==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 851
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
* Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
* Marjory L. Joseph, Introductory Textile Science, Holt, Rinehart and Winston, Fort Worth, TX, 1986
* J.Gordon Cook, Handbook of Textile Fibres:II Man-made Fibres, Merrow Publishing Co., Durham, England, 1984. p.444.
Category:Materials database
Violamine R

== Description ==
A synthetic violet color dye. Violomine R is often used as a stain in hematology and histology.
== Synonyms and Related Terms ==
violomine R; Acid Violet 9; CI 45190; Xanthylium, 9-(2-carboxyphenyl)-3-((2-methylphenyl)amino)-6-((2-methyl-4-sulfophenyl)amino)-, inner salt; 2-[3-[(2-methylphenyl)amino]-6-(2-methyl-4-sulfophenyl)iminoxanthen-9-yl]benzoic acid (IUPAC)
==Physical and Chemical Properties==
UV absorption max=529 nm
Composition 	C34H26N2O6S
CAS 	6252-76-2
Molecular Weight	590.65
== Resources and Citations ==
* Aldrich Chemical Catalog: http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/229385 (Nov 2008)
Category:Materials database
Violet

== Description ==
One of the basic colours of the visible light spectrum. Violet corresponds to the wavelength range 400 - 450 nm.
See: Colour
== Synonyms and related terms ==
purple; violet (Dan., Fr., Ned.); Purpur (Deut.); violeta (Esp., Port.); iodes (Gr.); viola (It.); fiolety (Pol.); violett (Sven.)
Category:Materials database
Violet carmine

== Description ==
An early name for a mixed violet compound made from cobalt blue and alizarin crimson. Violet carmine was not lightfast and is no longer in use.
==Resources and Citations==
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
Category:Materials database
Violet pigments

== Description ==
Violet is a color produced by light having a spectrum dominated by energy with a wavelength of about 400–450nm. It is considered a secondary color in the traditional RYB color wheel made by mixing blue and red. The shade of violet from the color wheel (halfway between blue and red) is represented by the following color coordinates: 
* Hex triplet: # 7F00FF
* RGB: (127, 0, 255); CMYK (0, 0, 0, 100) 
* HSV: (270°, 100%, 50%)
Examples of inorganic violet pigments:
* oxides (Mars violet)
* silicates (ultramarine violet) 
* phosphate (cobalt violet, manganese violet)
* other (purple of Cassius)
Examples of organic violet pigments:
* animal (murex)
* vegetable (archil)
* synthetic (mauve, magenta, methyl violet)
== Synonyms and Related Terms ==
purple pigments; magenta; violet (Dan., Ned.); Purpur (Deut.); pigmentos violeta (Esp.); añil (Esp.); pigments violets (Fr.); viola (It.); violaceus (Lat.); violett (Sven.); pigmentos violeta (Port.)
==Resources and Citations==
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall, Pigment Compendium, Elsevier Butterworth-Heinemann, Oxford, 2004
Category:Materials database
Virgin wool

== Description ==
A type of 'Woolmark' that indicates the fabric is made from 100% new wool. Virgin wool can not contain any reused wool. Virgin wool has also been used to refer to wool obtained from the first clipping of a sheep.
== Synonyms and Related Terms ==
lana virgen (Esp.)
==Resources and Citations==
* Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
* J.Gordon Cook, Handbook of Textile Fibres:I Natural Fibres, Merrow Publishing Co. , Durham, England, 1984
* Edward Reich, Carlton J. Siegler, Consumer Goods: How to Know and Use Them, American Book Company, New York City, 1937
* Website: www.fabrics.net
Category:Materials database
Viridian

== Description ==
A permanent green pigment composed of hydrated chromium oxide. Viridian is a synthetic pigment with characteristic deep green, transparent particles which are unaffected by light and chemicals. The process for making the hydrated form of chromium oxide was discovered in 1838 by Pannetier in Paris. A less expensive method for manufacturing viridian was patented by Guignet in 1859. Viridian, though not extremely popular because of its high price, was used as a pigment in all types of binding media. The stable pigment is also used as a colorant in concrete mixtures, rubber, inks, and automotive paints.
== Synonyms and Related Terms ==
chromium oxide hydrate; Pigment Green 18; CI 77289; transparent chrome oxide; vert émeraude (Fr.); Chromoxidhydratgrün (Deut.); Veridian (Deut); viridiana (Esp.); verde smeraldo (It.); viridiaan (Ned.); viridian (Port.); chromium oxide green transparent; chromium oxide dihydrate; French Veronese green; Pannetier's green; Mittlers' green; Guignet's green; Casali's green
[[[SliderGallery rightalign|Viridian, collodion slide (Forbes MFA 412), 532 nm- resize.tif~Raman (MFA)|Viridian, chromium oxide green (bottle 405).TIF~FTIR (MFA)|f412sem.jpg~SEM|f412edsbw.jpg~EDS|viridian.jpg~Chemical structure]]]
==Risks==
* Gamblin Colors: SDS
==Physical and Chemical Properties==
* Resistant to acids and alkalis. 
* Particle size irregular (0.07 - 20 micrometers). 
* Irregular undulose extinction in polarized light. 
* Bright green birefringent particles.
Composition 	Cr2O3.2H2O
CAS 	1308-38-9
Melting Point 	2435 C
Density 	3.32 g/ml
Refractive Index	1.62; 2.12
Boiling Point 	4000 C
==Resources and Citations==
* R. Newman, "Chromium Oxide Greens", Artists Pigments, Volume 3, E. West FitzHugh (ed.), Oxford University Press: Oxford, 1997. 
* The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996 Comment: "Pigments"
* R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966 Comment: p. 173
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Pigments Through the Ages - http://webexhibits.org/pigments/indiv/technical/viridian.html - refractive index: alpha and beta = 1.62; gamma = 2.12
* Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
* R.D. Harley, Artists' Pigments c. 1600-1835, Butterworth Scientific, London, 1982
* Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
* Wikipedia: http://en.wikipedia.org/wiki/Viridian (Accessed Sept. 20, 2005)
Category:Materials database
Viscose

== Description ==
1) A viscous orange color liquid of cellulose xanthate. Viscose is made by treating cellulose with sodium hydroxide then adding carbon disulfide. It is used in the manufacture of viscose rayon and cellophane.
2) Common name for viscose rayon.
== Synonyms and Related Terms ==
1) sodium cellulose xanthogenate; cellulose xanthate; 
2) viscose rayon
== Collection Risks == 
2) Links to Oddy Test results posted on AIC Wiki Materials Database Pages for individual materials below
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° John Ranger Textiles, Serge 65% polyester, 35% 100% viscose tested in 2016 
° Maish Felts, Royal felt: 100% viscose tested in 2010 
== Physical and Chemical Properties ==
Insoluble in organic solvents.
== Resources and Citations ==
* R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
* Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
* Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
* The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 10145
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Wikipedia: http://en.wikipedia.org/wiki/Viscose (Accessed Jan. 15, 2006)
Category:Materials database
Viscose rayon

== Description ==
Rayon produced from cellulose dissolved in sodium hydroxide, then treated with carbon disulfide to form an orange viscous solution of cellulose xanthate (viscose). The process for making viscose was discovered in 1892 by Charles Cross and Edward Bevan in England. Soon after the turn of the century, several companies began manufacturing viscose rayon and it quickly became the most important natural polymer fiber. Viscose has good washability and fair abrasion resistance. It dyes well and has good sunlight resistance. It is dyed with direct dyes at low temperatures. Viscose rayons are used for woven and nonwoven fabrics, rubbers, felts, tire cords, and cellophane. 
See also rayon.
== Synonyms and Related Terms ==
cellophane; rayon; viscose; Avtex; regenerated cellulose; artificial silk; wood silk; kuntsilke (Dan.); Kunstseide (Deut.); Viskosefasern (Deut.); viscose (Fr.); rayon viscosa (It.); rayon (Ned., Sven.)
[[[SliderGallery rightalign|ViscoseTestfabrics.jpg~FTIR|viscose250m.jpg~SEM|viscose1200m.jpg~SEM|Rayonsynthvt.jpg~Chemical process for viscose rayon]]]
== Collection Risks == 
Links to Oddy Test results posted on AIC Wiki Materials Database Pages for individual materials below
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° Khoon Heng show case fabric 65% polyester, 35% viscose tested in 2017 
° John Ranger Textiles, Serge 65% polyester, 35% 100% viscose tested in 2016 
° Maish Felts, Royal felt: 100% viscose tested in 2010 
== Physical and Chemical Properties ==
* Insoluble in most organic solvents. 
* Viscose fibers have continuous lengthwise striations. 
* Cross sections were originally circular with indentations; now may be dog bone or trilobal. 
* Tenacity = 2.0-2.6 g/denier (dry); 1.0-1.5 (wet); 
* Moisture regain = 11-16.6%; 
* Elongation = 15-13%; (dry); 20-40% (wet) ; 
* Melting point = 150 C (dec); 
* Density = 1.46-1.54 g/ml
* Burns with small flame, incandescent ash and odor of burnt paper.
== Comparisons ==
== Resources and Citation ==
* R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 654
* Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
* S.R.Trotman, E.R. Trotman, Textile Analysis, J.B. Lippincott Company, Philadelphia, 1932
* Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
* The Dictionary of Paper, American Paper Institute, New York, Fourth Edition, 1980
* J.Gordon Cook, Handbook of Textile Fibres:II Man-made Fibres, Merrow Publishing Co. , Durham, England
* History of Plastics at www.nswpmith.com.au/historyofplastics.html
* Wikipedia: http://en.wikipedia.org/wiki/Rayon (Accessed Jan. 15, 2006)
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
Category:Materials databaseCategory:MWG
Viscosity

== Description ==
The resistance of a liquid to flow. Viscosity is caused by the internal molecular friction. In cgs units, absolute viscosity is measured in centipoise (cP or cps). A hundred centipoise is one poise (P); one poise is equal to the movement of one gram of material the distance of 1 centimeter in one second. At room temperature, water has viscosity of 1.0 centipoise. In general, viscosity decreases with increasing temperature and pressure. The antonym of viscosity is fluidity.
== Synonyms and Related Terms ==
cp; centipoise; Viskosität (Deut.); viscosité (Fr.);
==Physical and Chemical Properties==
Example viscosities (in centipoise): 
* Water = 1 
* Olive oil = 81 
* Glycerol = 93 
* Corn syrup = 1381 
* Honey = 5000-10,000 
* Molasses = ~100,000 
* Peanut butter = ~250,000
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 946
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* ASTM, Standard Terminology Relating to Thermophysical Properties, Annual Book of ASTM Standards, Section 6, Paints, Related Coatings and Aromatics, ASTM, E1142, 695-696, Jul-94
* Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
* Richard C. Wolbers, Nanette T. Sterman, Chris Stavroudis, Notes for Workshop on New Methods in the Cleaning of Paintings, J.Paul Getty Trust, Los Angeles, 1990
* Encyclopedia Britannica, http://www.britannica.com Comment: "Viscosity." Accessed 6 Sept. 2004 .
* Paintings Specialty Group, Painting Conservation Catalog, Wendy Samet (ed.), AIC, Washington, DC, 1998
* Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
* Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
Category:Materials database
Visible radiation

== Description ==
The portion of the electromagnetic spectrum with wavelengths ranging from 380 - 770 nanometers (nm). Visible radiation falls between ultraviolet and infrared regions of the spectrum. The shortest visible light waves are violet and the longest are red. The effects of radiation are measured in terms of its quality (color), quantity (intensity) and duration (time). Isaac Newton first used the word spectrum in 1671 to described the colors of light dispersed by a glass prism.
== Synonyms and Related Terms ==
light; visible light rays; optical spectrum; visible spectrum; Lichtspektrum (Deut.); lumière visible (Fr.); espectro visível (Port.); espectro óptico (Port.)
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971
* Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
* Wikipedia: http://en.wikipedia.org/wiki/Visible_light (Accessed Sept. 20, 2005)
Category:Materials database
Vitreous enamel

== Description ==
A hard, glasslike protective coating on porcelain. See inorganic enamel.
== Synonyms and Related Terms ==
porcelain enamel; esmalte vítreo (Esp.); esmalte vítreo (Port.)
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 294
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
Category:Materials database
Vitriol

== Description ==
An obsolete name used for sulfates. The term vitriol originated in the 13th century in Albertus Magnus's book De Mineralbus, Liber V (Schur 1985). 
Some examples are: 
* Blue vitriol - copper sulfate 
* Green vitriol - ferrous sulfate 
* Red vitriol - hydrated cobalt sulfate 
* White vitriol - zinc sulfate 
* Oil of vitriol - sulfuric acid
== Synonyms and Related Terms ==
copperas; sal martis; sulfate of iron; chacantum (Gr.); attramentum (Lat.)
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p.785
* Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
* Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
Category:Materials database
Vitrolite

== Description ==
[Libbey-Owens-Ford] A brand name for laminated glass panels. Vitrolite panels had a sheet of clear glass bonded to a sheet of opaque, colored glass. They were commonly used from 1900-1940 (Bucher 1996). Vitrolite panels were used as wall veneers, marquees and spandrels.
See Structural glass
== Resources and Citations ==
* Carol Dyson, "Structural Glass", in Twentieth-Century Building Materials, T. Jester (ed.), McGraw-Hill: New York, 1995. 
* "The Preservation of Historic Pigmented Structural Glass (Vitrolite and Carrara Glass)", Preservation Brief 12, National Park Service. Link
* The Old House Web: 'Structural Pigmented Glass' link
Category:Materials database
Vivak clear 099

== Description ==
[Bayer MaterialScience AG] A clear transparent thermoplastic sheet composed of polyester terephthalate glycol. Vivak® clear 099 sheets are easy to machine, are formable at low temperatures, flame-retardant, and highly impact resistant. The sheets are marketed for use in displays, signs, containers, and shelving. Related products include: 
* Vivak 2099: UV coated sheets
* Vivak HT clear 099: softens at 91C
== Synonyms and Related Terms ==
Vivak 099; Vivak clear 099; clear099; Vivak 2099; Vivak HT clear 099
== Applications ==
* Book cradles
* Spacers
* Prosthetics
== Risks ==
== Physical and Chemical Properties ==
* Softening temperature = 80C
* Recyclable = code 2
* Density = 1.27
* Refractive Index = 1.567
==Forms and Sizes==
* Available in thicknesses of 0.512 mm (Europe and North America)
== Resources and Citations ==
* Bayer Polymers: Vivak technical sheet
* Plastics International: Vivak technical sheet
Category:Materials databaseCategory:MWGCategory:Board/Panel, Plastic Category:Glazing
Volatile oils

== Description ==
An oil that evaporates at room temperature. Volatile oil are distinguished from fixed oils with the paper test. When a drop of oil is placed on a paper, a volatile oil will not leave a spot while a fixed oil will. Volatile oils are generally distilled from plants. Essential oils are usually volatile oils.
== Synonyms and Related Terms ==
aceites volátiles (Esp.); aceites esenciales (Esp.); huiles volatiles (Fr.)
Category:Materials database
Volcanic

== Description ==
Igneous extrusive rock formed at the Earth's surface and having aphanitic structure. Volcanic rock is emitted by a volcano, which is an opening, or rupture, in a planet's surface or crust that allows hot magma, ash and gases to escape from below the surface.
== Synonyms and Related Terms ==
vulcânica (Port.); volcanique (Fr.)
==Resources and Citations==
* José Delgado Rodrigues, LNEC, Submitted information, 2009.
Category:Materials database
Volt

== Description ==
The SI derived unit of electric potential difference across a conductor when a current of one ampere dissipates one watt of power. Voltage is a measure of the strength or power of an electrical source for a given current level. It is named in honor of Alessandro Volta (1745–1827), who invented the the first chemical battery in 1800. Voltage is given in the SI units of m2 · kg · s-3. It can also be written as one joule of energy per coulomb of charge, J/C.
== Synonyms and Related Terms ==
V; voltage
Category:Materials database