Turquoise - 40M Years to Today

Chemically, turquoise is a complex mix of copper, aluminum, water, and phosphorous. The phosphorous bonds with the copper and aluminum to form phosphatic compounds of these metals. The inclusion of water makes the phosphates hydrous. Turquoise can also include several other minerals or elements including silica, iron, zinc and manganese. These other materials may be present in small quantities but can have a significant impact on the properties of the stone. For example, the presence of zinc can cause the color of turquoise to change to yellow. The best example of yellow turquoise is from the Damali mine in Nevada. Millions of years ago - about 40 million by some estimates - water flowing through and on the surface of rocks gradually broke down the constituents of the rock and carried the dissolved salts to hollows and crevices within the host bedrock. The solution dried with time and a mix of chemical salts was left behind. Under tectonic forces, these salts were mixed with silica and turquoise was formed. Silica - which was mentioned earlier as being one of the secondary minerals in turquoise - plays a key role in the quality of the specimen. If there was significant incorporation of silica during the formative stages of the stone, then the resulting specimen is hard and of high quality. On the other hand, it the infusion of silica was not complete, then the resulting stone has a moderate to low quality, which is the case with about 95 percent of turquoise produced today.

In relation to humans, the history of turquoise started around 4000 BC when Egyptians discovered turquoise in the Sinai Peninsula. There is actual recorded information that suggest that significant mining activity was going on at the mines in the Sinai during the reign of Senerkhet. Most gemologists and historians believe that the first discovery of turquoise took place in ancient Egypt. Others point to a silver turquoise pendant, turquoise beads, and necklaces found at archaeological excavations in ancient Mesopotamia (present day Iraq) dating back to 5000 BC as the earliest connection between humans and turquoise. The North American history of turquoise although a thousand years old, is relatively young in comparison to these previously mentioned civilizations. Turquoise was first mined at Cerrillos in New Mexico, and there is historical evidence that suggests that natives from this area were trading turquoise with the indigenous people of Mexico nearly six hundred years ago.

Turquoise today has risen in popularity and ranks number one among all opaque gemstones used in jewelry. The versatility of its blue color and darker vein patterns has made it a favorite of many. While innovative designs incorporating a turquoise beads in a white pearl necklace, or a combination of coral and turquoise for necklaces and bracelets are popular for fashion jewelry today, the classic turquoise inlay work in sterling silver settings from the Southwest remains the most popular genre of jewelry incorporating this gemstone.