Turquoise
Last updated: April 2026
An opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminum. Block/reconstituted ('Mohave') turquoise consists of powder and binder; detected by loupe (uniform texture, no matrix variation, mold marks on backs).
Physical & Optical Properties
Key Differentiators
- Opaque with waxy luster
- Characteristic blue to green color often with matrix
- Aggregate structure
Natural vs. Synthetic
Synthetic turquoise is commercially available (Gilson synthetic). Distinguishing natural from synthetic typically requires microscopic examination of internal features.
- Acetone test: Natural untreated turquoise: no reaction — swab stays clean, no color change. Synthetic: Dyed howlite/magnesite: blue-green color immediately transfers to acetone swab. Stabilized natural turquoise: may slightly dull surface with prolonged exposure but minimal color transfer.
- Hot needle test (stabilized): Untreated natural turquoise: no melting, no plastic smell. Synthetic: Stabilized turquoise (resin-impregnated): burning plastic smell, may leave sticky/melted spot. Confirms resin treatment.
- Visual / magnification: Irregular color distribution — spiderweb matrix with uneven dark veining, varying blue-green saturation, waxy luster, microcrystalline texture. Synthetic: Gilson: too-uniform color, absent or artificially regular matrix, characteristic 'sugar cube' or 'columnar' granular texture under 20x+. Dyed howlite: dye concentrates in surface fissures, chalky or porcelain luster.
- Hardness / SG: Turquoise H ~5–6, SG ~2.6–2.8. Synthetic: Howlite H ~3.5, SG ~2.5 — softer and slightly lighter. Magnesite H ~3.5–4.5, SG ~3.0. Practical hardness test with Mohs pencils separates these from turquoise.
GemID Pro includes a two-phase natural vs. synthetic testing protocol for Turquoise.
Start Free TrialCommonly Confused With
Commonly confused with: Variscite, Chrysocolla, Howlite Dyed, Plastic, Amazonite, Chrysoprase, Howlite.
Treatments
- Stabilized (resin-impregnated)
- Wax/Oil Impregnation
- Dyed (enhanced color)
- Simulated/Imitation (howlite, magnesite, plastic)
- Zachery Treatment (electrolytic/electrochemical — undetectable by standard instruments; EDXRF required to detect elevated potassium)
Price Context
Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.
Measurement Guides
Identifying a turquoise? GemID walks through these tests in order — RI, SG, fluorescence, and more.
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