Variscite

(repeating unit)AlPO₄·2H₂OIMA symbolVar^[1]Strunz classification8.CD.10Crystal systemOrthorhombicCrystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)Space groupPbcaIdentificationColorPale to emerald-green (pale green in transmitted light), green, blue green, yellow green, pale shades of brown or yellow, rarely red and colourless to whiteCrystal habitEncrustations and reniform massesCleavage[010] perfectFractureConchoidal to splinteryMohs scale hardness4.5LusterVitreous to waxyStreakWhiteDiaphaneityTransparent to translucentSpecific gravity2.57 to 2.61Optical propertiesBiaxial (−)Refractive indexnα = 1.563 nβ = 1.588 nγ = 1.594Birefringenceδ = 0.031References^[2][3][4]

Variscite is a hydrated aluminium phosphate mineral (AlPO₄·2H₂O). It is a relatively rare phosphate mineral. It is sometimes confused with turquoise; however, variscite is usually greener in color. The green color results from the presence of small amounts of trivalent chromium (Cr³⁺
).^[5]

Geology

Variscite is a secondary mineral formed by direct deposition from phosphate-bearing water which has reacted with aluminium-rich rocks in a near-surface environment.^[6] It occurs as fine-grained masses in nodules, cavity fillings, and crusts. Variscite often contains white veins of the calcium aluminium phosphate mineral crandallite.

It was first described in 1837 and named for the locality of Variscia, the historical name of the Vogtland, in Germany. At one time, variscite was called Utahlite. At times, materials which may be turquoise or may be variscite have been marketed as "variquoise". Appreciation of the color ranges typically found in variscite have made it a popular gem in recent years.^[7]

Variscite from Nevada typically contains black spiderwebbing in the matrix and is often confused with green turquoise. Most of the Nevada variscite recovered in recent decades has come from mines located in Lander County^[8] and Esmeralda County, specifically in the Candelaria Hills.

Notable localities are Lucin, Snowville, and Fairfield in Utah, United States. Most recently found in Wyoming as well. It is also found in Germany, Australia, Poland, Spain,^[9] Italy (Sardinia) and Brazil.

Jewelry

Variscite has been used in Europe to make personal ornaments, especially beads, since Neolithic times. Its use continued during the Bronze Age and in Roman times, although it was not until the 19th century that it was determined that all the variscite used in Europe came from three sites in Spain, Gavá (Barcelona), Palazuelo de las Cuevas (Zamora), and Encinasola (Huelva).^[10]

Variscite is sometimes used as a semi-precious stone, and is popular for carvings and ornamental use due to its beautiful and intense green color, and is commonly used in silversmithing in place of turquoise. Variscite is more rare and less common than turquoise, but because it is not as commonly available as turquoise or as well known to the general public, raw variscite tends to be less expensive than turquoise.^[7][5][11]

Gallery

• 
  Cut slab of variscite at the Smithsonian. Specimen is roughly 0.5 m wide.
• 
  Variscite filling the cracks in siltstone. The sample is from Queensland, Australia. The width of the view is 11 cm (4.3 in).
• 
  Polished variscite from Nevada
• 
  Variscite and silver bolo tie. This variscite specimen contains inclusions of white crandallite and is from Clay Canyon near Fairfield, Utah.

See also

• Variscan orogeny – Collision of tectonic plates resulting in the creation of mountains (same etymology, as named from the ancient locality of Variscia in Germany)
• List of minerals

References

FormsMaking

People	Bench jeweler Clockmaker Goldsmith Jewellery designer Lapidarist Silversmith Watchmaker
Processes	Carving Casting centrifugal lost-wax vacuum Enameling Engraving Filigree Kazaziye Metal clay Plating Polishing Repoussé and chasing Soldering Stonesetting Wire sculpture Wire wrapped jewelry
Tools	Draw plate File Hammer Mandrel Pliers

Materials

Precious metals	Gold Palladium Platinum Rhodium Silver
Precious metal alloys	Britannia silver Colored gold Crown gold Electrum Shakudō Shibuichi Sterling silver Argentium Tumbaga
Base metals	Brass Bronze Copper Mokume-gane Nickel silver (alpacca) Pewter Pinchbeck Stainless steel Titanium Tungsten
Mineral gemstones	Agate Amazonite Amethyst Aventurine Beryl (red) Carnelian Chrysoberyl Chrysocolla Diamond Diopside Emerald Fluorite Garnet Howlite Jade Jasper Kyanite Labradorite Lapis lazuli Larimar Malachite Marcasite Moonstone Obsidian Onyx Opal Peridot Prasiolite Quartz (smoky) Ruby Sapphire Sodalite Spinel Sunstone Tanzanite Tiger's eye Topaz Tourmaline Turquoise Variscite Zircon
Organic gemstones	Abalone Amber Ammolite Copal Coral Black Precious Ivory Jet Nacre Operculum Pearl Tortoiseshell
Other natural objects	Bezoar Bog-wood Ebonite (vulcanite) Gutta-percha Hair Shell Spondylus shell Toadstone

Terms