Turquoise: Turquoise is a blue-green mineral, has been and is highly regarded as semi-precious stone for thousands of years because of its unsurpassed color. It is a material widely used in jewelry worldwide.

Properties
 
Even the finest of turquoise is quite fragile, reaching a maximum hardness of just under 6 on the Mohs scale, is a cryptocrystalline mineral crystals and rarely as simple and all its properties are highly variable.
The bright turquoise is waxy to almost glassy, ​​and is usually opaque, although it may be semi-translucent in small sections. Color is as variable as the rest of their properties, ranging from white to dark blue and sky blue and from blue-green to green-yellow. The blue color is attributed to copper, while the green may be the result of iron impurities or dehydration.
 
Deposits and exploitation

It is a rare mineral of secondary education and is found mainly in desert regions. Turquoise is among the first gems to be mined.
However, turquoise is sometimes obtained as a byproduct of copper mining on a large scale, especially in Peru.

In the city of Ica-Peru are significant deposits tuquesas.
 
Value and care

The purity of color is the factor determining the value of a turquoise: In general, most prized color is dark blue, the value decreasing with increasing shades of green.
The rock in which turquoise is found can sometimes be seen as an irregular spot or as a network of veins that cut brown or black stone.