What is Turquoise?
Turquoise is a renowned gemstone for its characteristic blue-green color ranging from lighter and translucent shades to deeper and opaque ones. It is widely appreciated for its unique and distinctive beauty, making it one of the most desired stones in the world of jewelry and artistic craftsmanship.
Chemically, turquoise is primarily composed of hydrated copper phosphate, but it may also contain traces of other minerals such as calcite, limonite, and pyrite, which influence its coloration and composition. It forms in geological environments containing copper-rich rocks and phosphate minerals. This formation process can take millions of years and involves mineral deposition under low oxygen conditions.
Turquoise mines are found in various parts of the world, with some of the most famous located in the United States (such as Arizona and New Mexico), Iran, China, and other regions rich in sedimentary rocks containing copper and phosphate minerals. Turquoise extraction methods may vary, but generally involve the excavation and processing of rocks containing the mineral.
Currently, there are two common treatments performed on turquoise:
Enhanced turquoise is the result of an electrochemical process known as the Zachery method, in which natural turquoise is immersed in a bath of minerals similar to those found in natural turquoise and subjected to an electric current. This procedure reduces the stone's porosity, enhances its natural color, and increases its hardness without the use of plastic materials. Contrary to what one might think, enhanced turquoise represents some of the best quality turquoise, as only medium to high-quality turquoise can withstand the Zachery method; lower-quality turquoise would risk damage or crumbling. Enhanced turquoise can be identified through spectroscopic analysis.
Stabilized turquoise is the most common type of turquoise available on the current market. Since much of the extracted turquoise is unusable in its natural state, stabilization allows for its improvement. This process involves immersing lower-quality turquoise in an epoxy resin. This treatment not only makes the stone more durable but also intensifies its color. This technique can be applied to all types of turquoise, whether low or high quality.
Delving into the cultural history of turquoise, its relevance across various ancient civilizations emerges. Ancient Egyptians, for example, considered it a sacred stone associated with the goddess Hathor and used it to create jewelry and amulets, as well as including it in tombs as a symbol of protection for the journey to the afterlife. Persians, on the other hand, used it to decorate valuable objects, attributing protective and courageous powers to it. Pre-Columbian civilizations of the Americas, such as the Aztecs and the Maya, considered it a symbol of fertility and abundance, using it in jewelry and ritual objects. Today, turquoise remains popular, used in crystal therapy and meditation to promote energy balance and mental serenity, as well as being a sought-after stone in the world of high fashion and luxury jewelry.