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Chrysocolla

Last updated: April 2026

A hydrated copper silicate. The ranges in this entry are the mineral's: hardness 2–4, SG 1.93–2.40, RI 1.575–1.635, orthorhombic (Handbook of Mineralogy). Material intergrown with quartz — chrysocolla chalcedony, traded as gem silica — is a harder and denser material (hardness to ~7, SG ~2.58–2.64) and is not described by these ranges.

Chrysocolla has a specific gravity of 2.20 and a refractive index of 1.575–1.635, with a Mohs hardness of 2.0–4.0. It is aggregate.

Physical & Optical Properties

RI Range1.575–1.635
SG Range1.93–2.40
SG Typical2.20
Hardness (Mohs)2–4
Crystal SystemOrthorhombic
Optic CharacterAggregate
Dispersion0.000
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterInert
PleochroismNone
ColorsGreen, Blue Violet
SpeciesChrysocolla
GreenBlue Violet

Measured with a polariscope, a refractometer, a hydrostatic balance, a Chelsea filter, a UV torch, a loupe, a darkfield loupe and a spectroscope — step-by-step for each.

Through the refractometer

Chrysocolla varies 1.575 – 1.635 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 REFRACTIVE INDEX DORotate the stone through a full 360°, watching the boundary. SEEOne boundary that does not move as you rotate — and it isoften vague rather than crisp. Where it sits is not fixedfor this species: published at 1.575 – 1.635, and the stonedrawn here reads 1.605, between the dashed marks. MEANSThis is an aggregate — a mass of microscopic crystals — andon this instrument it looks exactly like a singly refractivestone. The refractometer cannot tell the two apart. Thepolariscope can: an aggregate stays light through a fullrotation, where a singly refractive stone stays dark. Computed from gems.json — edge positions are arithmetic, not drawn. RI increases upward; the field above the boundary is the dark one.

Drawn from the refractive index above, on a 1.40–1.81 scale. How to take this reading.

Key Differentiators

Common Simulants

Commonly Confused With

Commonly confused with: Turquoise.

Treatments

Measurement Guides

How to Identify a GemstoneHow to Measure Specific GravityHow to Use a RefractometerUV Fluorescence Testing

Identifying a chrysocolla? Loupewise walks through these tests in order — RI, SG, fluorescence, and more.

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Studying for the GIA, FGA, or FEEG practical? Chrysocolla is one of the 132 species in Loupewise’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.

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