Back to gem encyclopedia


Azure sky, robin’s egg blue: Vivid shades of turquoise define the color that’s named after this gem.

Responsive image

This turquoise is cut in a cabochon: the most common shape.

Responsive image
Robin’s egg

The preferred color for turquoise is a pure sky blue.

Responsive image

Some buyers prefer the presence of matrix in fashioned turquoise.

Responsive image
Responsive image

Turquoise is an aggregate of microscopic crystals that form a solid mass.

Responsive image

The intense blue color in this rough is due to the presence of copper.

Responsive image

Veins of matrix in this turquoise are remnants of its surrounding rock.

Responsive image


About Turquoise

About Turquoise
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.

Turquoise Description Turquoise History and Lore

Birthstones & Anniversaries

Turquoise is the traditional birthstone for the month of December and the gem of the 11th anniversary.

4,000 BC

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.


  • Mineral: Turquoise
  • Chemistry: CuAl6(PO4)4  (OH)8.5H2O
  • Color: Blue to green
  • Refractive Index: 1.610 to 1.650
  • Birefringence: Not detectable
  • Specific Gravity: 2.76 (+0.14, -0.36)
  • Mohs Hardness: 5 to 6

Where It's Found



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
gem love

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.

Quality Factors

Turquoise is judged on its color, texture, and the absence of matrix.


quality factors

The even blue color of this cabochon would be called Persian blue in the trade.


quality factors

These free-form turquoise cabochons show a typical matrix pattern.


quality factors

Although turquoise is usually cut into beads and cabochons, it can also be carved.

Carat Weight

quality factors

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.

A Survey of the Gemstone Resources of China

Peter C. Keller and Wang Fuquan , Mar 1, 1986 Read Article

Gem Localities of the 2000s

James E. Shigley, Brendan M. Laurs, A. J. A. (Bram) Janse, Sheryl Elen, and Dona M. Dirlam , Sep 6, 2010 Read Article