Turquoise is found in only a few places on earth: dry and barren regions where acidic, copper-rich groundwater seeps downward and reacts with minerals that contain phosphorus and aluminum. The result of this sedimentary process is a porous, semitranslucent to opaque compound of hydrated copper and aluminum phosphate.
Birthstones & Anniversaries
Turquoise is the traditional birthstone for the month of December and the gem of the 11th anniversary.
Turquoise buried in Ancient Egyptian tombs is among the world’s oldest jewelry.
Ancient Egyptians called turquoise “mefkat,” which also means “joy” and “delight.”
Montezuma, thinking Cortes was Quetzalcoatl, gave him the god’s favorite gem: turquoise.
CuAl6(PO4)4 ·(OH)8 ·5H2O
Blue to green
1.610 to 1.650
2.76 (+0.14, -0.36)
- Mohs Hardness: 5 to 6
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.Learn More
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.Learn More
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.Learn More
Why We Love This Gemstone
The spiderweb of veins that appear in turquoise are matrix: evidence of the surrounding rock.
A legacy of turquoise appreciation spans the globe, from ancient Egypt to Mesoamerica to China.
Turquoise is colored by copper, which creates some of the most vivid blues and greens in gems.
Turquoise is judged on its color, texture, and the absence of matrix.
The even blue color of this cabochon would be called Persian blue in the trade.
These free-form turquoise cabochons show a typical matrix pattern.
Although turquoise is usually cut into beads and cabochons, it can also be carved.
Cutters work around large areas of matrix to yield pieces of evenly colored turquoise.
Turquoise Quality Factors: The Comprehensive Guide
Explore sources, gemological research, and the role of gems in history.
Turquoise from Zhushan County, Hubei Province, ChinaQuanli Chen, Zuowei Yin, Lijian Qi, and Yan Xiong , Oct 24, 2012 Read Article
The Allure of Turquoise
Turquoise: Mines, Mineral, & Wearable Art
Mark P. Block
Turquoise Unearthed : An Illustrated Guide
Joe Dan Lowry and Joe P. Lowry