Physical & Optical Properties

RI Range1.544–1.553
SG Range2.64–2.71
SG Typical2.65
Hardness (Mohs)7
Crystal SystemTrigonal
Optic CharacterAggregate
Dispersion0.013
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterInert
PleochroismNone
ColorsBlue Violet, Green
SpeciesQuartz
Blue VioletGreen

Key Differentiators

Treatments

Price Context

Natural — low ($/ct)$1
Natural — high ($/ct)$15
NotePer carat; less common than Tiger's Eye; value driven by depth and uniformity of blue color and chatoyancy quality

Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.

About Hawk's Eye

Blue-grey to blue-green chatoyant quartz formed where crocidolite asbestos is replaced by silica without iron oxide oxidation (which produces golden Tiger's Eye). The retained blue color of the asbestos gives Hawk's Eye its steely blue-grey to greenish-blue hue. Always cut en cabochon. Often found alongside Tiger's Eye in the same host rock.

Identifying a hawk's eye? GemID walks through these tests in order — RI, SG, fluorescence, and more.

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