Turquoise
Other Silicates & Gemstones
Turquoise is an opaque blue-to-green hydrated copper aluminium phosphate. It normally forms as fine-grained veins or nodules rather than visible single crystals; copper supplies the blue color, while iron and remnants of host rock can contribute green tones and brown or black matrix patterns.
Identity
- Material or variety
- Turquoise
- Scientific or material identity
- Turquoise
- Classification
- Natural mineral or mineral variety
- Composition or formula
- CuAl₆(PO₄)₄(OH)₈·4H₂O
- Crystal system or structure
- Triclinic
- Geological or manufacturing origin
- Can form in more than one geological environment, or combines several materials.
- Mohs hardness
- 5 to 6
Origins
China · Iran · Kenya · Mexico · USA
Appearance & optical properties
opaque sky-blue turquoise with brown spiderweb matrix.
History & discovery
Turquoise has been used for adornment for thousands of years: ancient Egyptian rulers wore it, and Chinese artisans carved it more than 3,000 years ago. Its name came through French for “Turkish stone,” reflecting the trade route by which Persian material reached Europe rather than its geological origin.
Uses & care
- Common uses
- Turquoise is cut into cabochons and beads for jewelry and is also carved into small figures or fitted into decorative inlay.
- Handling and cleaning
- Clean with warm soapy water only; never use steam or ultrasonic cleaners. Keep turquoise away from high heat, acids, solvents, cosmetics, skin oils, and perspiration, which can discolor or damage its surface.
Jewellery
6 pieces of Turquoise jewellery. Learners earn each one in DigMyGem by learning words; until then it shows as a silhouette.
Double-headed serpent
Jewel
An Aztec pectoral of cedar wood covered in a mosaic of turquoise, with two serpent heads and red and white shell details. It was likely brought to Europe by Hernan Cortes and is now in the British Museum.
Photo: Geni, CC BY-SA 4.0, via Wikimedia Commons 
Turquoise Mosaic Diadem
Crown
A diadem of turquoise tesserae on a gold frame, made for an Aztec fire-priest to wear at the new-fire ceremony. The blue tiles were said to hold the colour of the year itself.
Silver and Turquoise Cuff
Bracelet
A heavy silver cuff set with rows of sky-blue turquoise cabochons, in the style of the American Southwest. It is left smooth at one end, as if the maker meant to add more stones.
Marie Louise Diadem
Tiara
A diamond and turquoise diadem made for Marie Louise of Austria, wife of Emperor Napoleon, and now on permanent display at the National Museum of Natural History in Washington, D.C.
Photo: Alvesgaspar, CC BY-SA 4.0, via Wikimedia Commons 
Crown of Bahadur Shah Zafar
Crown
A jewelled headdress of gold, turquoises, rubies, diamonds, pearls and emeralds worn by the last Mughal emperor, Bahadur Shah Zafar, in the mid-19th century. It was taken to Britain after the Indian Rebellion of 1857.
Crown of Stephen Bocskai
Crown
A crown given by the Ottoman sultan to Stephen Bocskai, Prince of Hungary and Transylvania, in the early 17th century, made of gold with rubies, spinels, emeralds, turquoises and pearls.
Photo: Michal Maňas, Public domain, via Wikimedia Commons
