Where is Turquoise found?

Turquoise occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.

Where to find Turquoise

Collecting tips

1. Look for Copper Deposits. Turquoise is a secondary mineral of copper, so search in areas known for copper mineralization, especially in arid or semi-arid regions. Look for signs of oxidized copper minerals like malachite (green) and azurite (blue).
2. Examine Altered Rocks. Focus on areas with altered volcanic rocks (rhyolite, andesite) or sedimentary rocks (sandstone, shale) that show signs of hydrothermal alteration. Turquoise often forms in veins, seams, and nodules within these host rocks.
3. Check Fractures and Cavities. Turquoise typically precipitates in open spaces. Inspect fractures, fissures, and vugs within the host rock for blue or green mineral fillings. It can also occur as botryoidal or reniform masses.
4. Observe Color and Luster. The characteristic blue-to-green color and waxy to subvitreous luster are key indicators. Be aware that other minerals like chrysocolla or variscite can have similar appearances, so further tests may be needed.
5. Consider Hardness. Turquoise has a Mohs hardness of 5-6. This can help differentiate it from softer minerals. A steel file (hardness ~6.5) will scratch turquoise, but turquoise will scratch glass (hardness ~5.5).
6. Safety Precautions. When collecting in mining areas, be aware of unstable ground, old mine workings, and potential exposure to dust. Always wear appropriate personal protective equipment (PPE) such as gloves, eye protection, and a dust mask, especially if breaking rocks. While turquoise itself is not acutely toxic, prolonged inhalation of dust from any rock can be harmful. Always wash hands after handling minerals.

Quick Check

Color:

Sky-blue to greenish-blue

Luster:

Waxy to subvitreous

Streak:

White to pale bluish-green

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