Indian Mountain turquoise is, despite the name, a turquoise from the southwestern United States rather than from India. The mine sits in the Tobin Range area of Lander County, Nevada, and produced material primarily through the second half of the twentieth century. The name has caused recurring confusion in the trade because buyers unfamiliar with American turquoise nomenclature read "Indian" as a country reference; in practice it points to the Indian Mountain locality and not to the subcontinent, which produces no commercially significant turquoise of its own.

Locality and material

Nevada is the most prolific turquoise-producing state in the United States, and Indian Mountain is one of dozens of small mines scattered across its central and northern ranges. The deposit produced material in two principal habits: a hard, light to medium blue stone with a pale matrix in webbed or spider patterns, and a green to blue-green stone with darker brown to black matrix. The blue webbed material is the variety most associated with the name and the variety that retail customers most often encounter in mid-century and contemporary Native American silverwork.

Hardness in the better Indian Mountain rough sits in the upper range for natural turquoise, around 5 to 6 on the Mohs scale, which is one of the reasons the material has been used in functional jewellery without the stabilisation treatments that softer turquoises require. Specific gravity falls in the standard turquoise range of approximately 2.6 to 2.9. Refractive index, where measurable on a polished surface, sits at roughly 1.61 to 1.65, again typical for natural turquoise.

Production and scarcity

Indian Mountain has not been a high-volume producer at any point in its history, and its output is small relative to better-known Nevada mines such as Number Eight, Lone Mountain or Royston. Production has been intermittent and small-scale, and most material in circulation today comes from older stockpiles held by lapidaries and silversmiths rather than from current mining. Like many of the small Nevada mines, Indian Mountain is effectively closed to active commercial extraction, and the available rough is finite.

Trade context and verification

The name Indian Mountain is used in the American Southwest turquoise trade alongside dozens of other mine-of-origin names that function as both provenance and grade descriptors. Because turquoise from any single mine can vary widely in colour and matrix character, attribution to a specific mine is generally a matter of dealer expertise and chain of custody rather than a diagnostic test that a gemmological lab can perform. AGTA and the GIA have both noted that turquoise origin determination is, with few exceptions, not within the scope of standard testing protocols, and that buyers relying on mine-name attributions should know and trust the source of the material.

For the gemmologist or trade buyer, the working approach is straightforward: treat the mine name as a description of style, colour and matrix character rather than as a guaranteed locality, unless the chain of provenance back to the mine is documented. The material itself, regardless of attribution, should be tested to confirm that it is natural rather than stabilised or reconstituted, and to confirm that it is turquoise rather than one of the look-alikes such as variscite, chrysocolla, or imitation block.

The naming confusion

Indian Mountain is not the only Nevada turquoise locality with a name that creates international confusion. Buyers in markets where American mine names are not common reference frequently mistake "Indian Mountain" for a subcontinental source and "Persian Blue" for a literal Iranian provenance when used as a colour descriptor for American material. The corrective is awareness: a turquoise sold as Indian Mountain by a reputable American dealer is, on the dealer's understanding, Lander County, Nevada material; a turquoise sold as Indian by a vendor with no clear American Southwest connection should be questioned and verified.

The deposit's name itself derives, by local report, from the geological feature called Indian Mountain in the surrounding terrain rather than from any reference to people. The mine name has been in use since at least the mid-twentieth century and is documented in surveys of Nevada turquoise deposits.