How to identify Red Tiger's Eye
Quartz (macro-crystalline variety)
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Open the appTo correctly identify Red Tiger's Eye (Quartz (macro-crystalline variety)), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.
Step-by-step identification
- 1
Color
Overall color and any zoning or banding
Ranges from reddish-brown to brick-red, often with darker bands. The color is due to oxidized iron inclusions.
- 2
Luster
How the surface reflects light: metallic, vitreous, dull
Silky to vitreous when polished, exhibiting a strong chatoyancy.
- 3
Texture
Grain size and surface feel: coarse, fine, glassy
Fine-grained, fibrous appearance internally, but feels smooth when polished. The fibrous structure is visible as parallel lines or bands.
- 4
Crystal Form
Shape of visible crystals or crystal faces
Massive, cryptocrystalline aggregates, typically forming veins or layers. Does not form macroscopic individual crystals.
- 5
Cleavage
How it breaks: flat cleavage planes vs irregular fracture
None, due to its cryptocrystalline nature. Exhibits conchoidal fracture.
- 6
Geological Environment
The rock formation and setting where it occurs
Found in highly metamorphosed banded iron formations, where crocidolite asbestos has undergone silicification and subsequent oxidation. Often occurs in association with other quartz varieties and iron-rich minerals.
Key Facts
- Hardness
- 7 (Mohs scale)
- Specific Gravity
- 2.64 - 2.71
- Crystal System
- Trigonal
- Color
- Reddish-brown to brick-red
- Luster
- Silky to vitreous
- Transparency
- Opaque to translucent
- Fracture
- Conchoidal to splintery
- Cleavage
- None
- Composition
- Silicon dioxide (SiO2) with fibrous inclusions of iron oxides (hematite) pseudomorphing after crocidolite
Physical characteristics
- Crystal Habit: Massive, fibrous aggregates, pseudomorphous after crocidolite
- Cleavage Type: None
- Fracture Type: Conchoidal to splintery
- Tenacity: Brittle
- Luster Type: Silky (due to fibrous inclusions) to vitreous (of the quartz matrix)
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