Cuprite
Last updated: April 2026
A copper oxide mineral known for its intense red color, but is too soft for most jewelry applications.
Cuprite has a specific gravity of 6.14 and a refractive index of 2.849, with a Mohs hardness of 3.5–4.0. It is singly refractive.
Physical & Optical Properties
RI Range2.849
SG Range5.85–6.15
SG Typical6.14
Hardness (Mohs)3.5–4
Crystal SystemCubic
Optic CharacterSR (Singly Refractive)
Dispersion0.155
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterInert
PleochroismNone
ColorsRed Pink, Brown
SpeciesCuprite
Key Differentiators
- Deep red color with metallic/adamantine luster
- Very high specific gravity
- Singly refractive with very high RI
Price Context
Natural — low ($/ct)$100
Natural — high ($/ct)$500
NotePer carat; extremely rare faceted gem; very soft (3.5–4 Mohs) — collector's stones only
Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.
Measurement Guides
Identifying a cuprite? GemID walks through these tests in order — RI, SG, fluorescence, and more.
Try GemID Free →Studying for the GIA, FGA, or FEEG practical? Cuprite is one of the 130 species in GemID’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.
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