Falcon's Eye
A variety of Tiger's Eye
What is Falcon's Eye?
Falcon's Eye is a blue-gray to blue-green opaque gemstone. It is famed for its movable optical reflectance, or cat’s eye effect. It has a silk-like finish, which is the result of tiny asbestos fibers that are encased in quartz. These fine layers of quartz reflect light and give the stone its characteristic sheen.
Optical Properties
- Refractive Index
- 1.534-1.540
- Birefringence
- 0.009
- Pleochroism
- None
- Optical Character
- Biaxial positive
- Dispersion
- 0.013
Discover Values
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Falcon's Eye before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Falcon's Eye Localities Map
See where Falcon's Eye is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Health & Safety Information
- ⚠️Falcon's Eye in powdered form can be toxic due to its Crocidolite Asbestos, Crystalline Silica content.
- ⚠️Beware of asbestos. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer. And it can take years for symptoms related to the exposure to appear. Lapidaries should exercise caution when cutting this mineral.
- ⚠️Falcon's Eye is typically non-toxic except in powder form. If you plan to cut or polish falcon's Eye, it's advisable to wear a dust mask to avoid inhaling any dust. Asbestos fibers and silica dust are hazardous when inhaled, as they can lead to serious lung disease.
Quick Facts
Physical Properties
- Color
- Blue, blue-grey, blue-green, brown
- Hardness (Mohs)
- 6.5 - 7
- Density
- 2.64 - 2.71 g/cm³
- Streak
- White
- Luster
- Silky, Vitreous
- Crystal System
- Trigonal
Chemical Properties
- Chemical Formula
- SiO2
- Elements
- O, Si
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Falcon's Eye FAQs
How do I identify Falcon's Eye?
Falcon's Eye can be identified by its hardness of 6.5 - 7 on the Mohs scale, Blue color, Silky, Vitreous luster, Trigonal crystal system. Look for these key characteristics when examining specimens.
What color is Falcon's Eye?
Falcon's Eye typically appears in Blue, blue-grey, blue-green, brown. Color can vary depending on impurities and formation conditions.
How hard is Falcon's Eye?
Falcon's Eye has a hardness of 6.5 - 7 on the Mohs scale. This gives it moderate hardness.