Turquoise: A Gorgeous Shade of Green-Blue

Turquoise color has been a favorite since ancient times because of its cheerfulness, unusualness and rarity of pigment. It reminds us of the tropical sea, vacation and luxury. It is a greenish-blue color that has several shades, from those that are more green to those that are more blue. Along with azure, cyan, cobalt and Prussian blue, it is one of the most famous shades of blue.

The color got its name from the mineral turquoise, which in French and English is turquoise, meaning “Turkish”. However, the mineral turquoise is not actually from Turkey, but came to Europe via Turkey (more precisely, the Ottoman Empire). Large deposits of turquoise are in Iran, especially in the province of Greater Khorasan.

However, Iran is not the only area where turquoise is found. Large quantities are also found in Sinai, from where they were exploited for the needs of the Egyptian rulers. A number of art objects, including the death mask of Tutankhamun, are made of or have inlays of turquoise. The mask of Tutankhamun has, in addition to gold and turquoise, also lapis lazuli, another blue mineral of unusual beauty. This shade was also a favorite in ancient Egypt for making decorations – tableware and figurines such as the figurine “William” the hippopotamus, which, although not made of turquoise, but of quartz (no clay, although these figurines are labeled as “ceramic”) it has that beautiful color that has been preserved not for centuries, but for millennia.

 

Turquoise is also found in South America, where it was a favorite among the Aztecs and Mayans. There are in Mexico, examples of copper runes in the province of Sonora, but also in China, Australia, the United States, especially New Mexico, Nevada and Arizona.

 

There is turquoise where there is plenty of copper. This semi-precious stone, so valuable to many, has, of course, become a victim of pseudoscience and claims that it has some magical energy or protects the wearer. Regardless of the new age mambo jumbo that has gathered around this mineral, it must be admitted that it is difficult to remain immune to its beauty.

But, in fact, turquoise, like other minerals, has a very ordinary composition – it is a type of aluminum-copper phosphate. Just like a diamond, which is nothing but tightly packed carbon, or rubies and sapphires, which are the mineral corundum, aluminum oxide in composition.

What is interesting about this mineral is the way it is formed. Actually ways, because scientists believe that there is not only one way in which it is created. It forms where water rich in minerals seeps into rocky voids. Over time, only minerals remain – like turquoise. Copper in turquoise gives it shades of blue and green.

Dissolved oxygen in the water oxidizes the copper sulfides into soluble sulfates, and the copper-rich acidic solution then reacts with the aluminum and potassium minerals in the host rock to precipitate turquoise. This usually fills spaces in volcanic rocks or phosphate-rich sediments.

There is a story that turquoise changes color, darkens if the owner of the stone (person wearing turquoise) is in danger, if he/she is threatened with death. The New Age story goes that if the “energy” in the room changes, the turquoise changes color to “warn the owner”. However, these old wives’ tales have more to do with chemistry than with the announcement of danger: Turquoise can indeed change color due to the action of the sun’s rays, but also cosmetics that a person applies to himself, and sweat.

Namely, turquoise is very porous, and as it consists of the metal aluminum, copper and sometimes some iron, and all these metals oxidize (that is, they rust), so does turquoise, due to the presence of water, oil, changes in the pH value due to the influence of the composition of the skin, can change color.