Turquoise

What it is

Turquoise is an opaque mineral that ranges from sky blue to green. It is a hydrous phosphate of copper and aluminium. The stone has been used as a gem for millennia because of its unique hue. Finer grades are rare and highly valued.

Where it comes from

The name comes from Old French for Turkish. This is because the stone reached Europe through Ottoman traders. The mines were actually in Persia. Ancient Greeks called it callais. Aztecs knew it as chalchihuitl. Scientific names like kalaite fell out of use by the nineteenth century.

How it is done

Turquoise forms when rainwater percolates through copper-rich rock. The water dissolves copper sulfides and reacts with aluminum minerals. This process happens at low temperatures in arid climates. Deposits fill veins in volcanic rock or sediment.

Tools and materials

The mineral contains copper which gives it blue color. Iron impurities create green shades. It has a waxy luster and a hardness of five to six on the Mohs scale. It is often found in massive or nodular forms rather than crystals.

What it is for

People have prized turquoise for its beauty and rarity. In Iran, the intense blue symbolized heaven on earth. Native Americans mined it for tools and ornaments. Egyptians used it in jewelry and amulets. Its value lies in its color and durability.

Who does it

Mining is often small-scale and seasonal. Workers use hand tools in remote areas. Historically, royal courts squandered accumulated dust. Modern operations face high costs and regulations. Some mines have closed due to economic shifts.

Peoples and places

Persians mined near Nishapur for two thousand years. Egyptians worked the Sinai Peninsula since the First Dynasty. Native Americans in the Southwest used stone tools. The Aztecs valued it deeply. Different regions produce stones with distinct colors and qualities.

What people believe

The stone's color was linked to spiritual concepts. In Iranian architecture, domes were covered in turquoise to represent the sky. Egyptians associated it with deities like Hathor. The stone's stability and brightness made it a powerful symbol.

When it is done

Mining often follows seasonal patterns due to weather risks. Flash floods threaten miners in the rainy season. Collapse of mine walls is a constant danger. Operations pause during harsh conditions.

How scholars and sceptics see it

Mineralogists study its triclinic crystal structure. X-ray diffraction reveals its composition. Researchers note its variability in hardness and porosity. The relationship between copper content and color is well documented.

Compare and confuse

Chrysocolla is a similar mineral but softer. Odontolite is fossil bone altered by phosphate minerals. Turquoise is distinguished by its greater hardness and specific chemical formula.

Law and persecution

Federal regulations affect modern mining operations. Some famous mines have ceased production due to costs. Historical sites are depleted. Legal frameworks govern current extraction efforts.

Today

Arizona is a major producer by value. Sleeping Beauty Mine closed in 2012. Kingman Mine still operates. Bedouin peoples quarry Sinai deposits sporadically. The market includes treated and synthetic stones.

Questions people ask about Turquoise

Good reading and sources

• Encyclopaedia BritannicaArticle
• How turquoise became synonymous with New MexicoNational Geographic, Article

• Turquoise on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos and video
• Wikidata recordOpen data