Turquoise is a precipitant, a rock that forms from water passing through mineral rich earth where it becomes concentrated. Copper is what gives turquoise its blue color. The presence of iron and zinc makes it more green. Every turquoise mine has a unique look and color which is one reason being able to identify which mine a turquoise stone comes from is very important in determining the stone and the jewelry’s value. While other gemstones like diamonds are most valued for their purity, it’s the impurities in the cracks known as the “matrix” in the turquoise stone that gives it its unique character and value.
Bisbee turquoise can range from a very light blue all the way through to dark blue with a chocolate colored chert matrix that's what really brings it alive. Kingman is famous for its fine spider web matrix. Lander Blue is the most valuable turquoise today that has an amazing looking very dark deep blue color with lots of matrix. Other important mines are Number 8, Sleeping Beauty, Royston, Morenci that are important to be able to identify to know the authenticity and true value of the turquoise stone.