Mineral Class: Phosphate
Crystal System: Triclinic
Hardness: 5 - 6
Luster: Waxy, Subvitreous
Colors: Blue, Green, Brown, White
Source: Australia, Afghanistan, Chile, China, Iran, Israel, Mexico, and USA
.Turquoise is a saturated blue-green mineral that is a hydrated phosphate of copper and aluminum. The luster of turquoise is typically waxy to sub-vitreous, and its transparency is usually opaque, but may be semi-translucent in thin sections. Color is as variable as the mineral's other properties, ranging from white to a powder blue to a sky blue and from a blue green to a yellowish green. The finest of turquoise reaches a maximum Mohs hardness of just under 6, or slightly more than window glass. Rare and desirable for its higher quality grades, this gemstone has been prized and valued since ancient times. Pliny the Elder referred to the stone as Callais, and the Aztec called it Chalchihuitl. The word “turquoise” dates to the 17th century and is derived from the French “turquois” meaning "Turkish" because the mineral was first brought to Europe through Turkey from mines in the historical Khorasan of Iran (Persia). Just as the color blue, Turquoise represents wisdom and tranquility.