Pietersite Identification Guide
How to identify pietersite by its chaotic swirling chatoyancy, brecciated texture, and storm-like blue, gold, and red color play.
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What Pietersite Looks Like
Pietersite is a brecciated, chatoyant variety of quartz that contains the fibrous remains of altered amphibole (crocidolite-type fibers). Its hallmark is a swirling, chaotic "tempest" of fibrous sheen rather than the neat parallel bands of tiger's eye.
- Color: Stormy mixes of slate blue, blue-grey, gold, brown, and reddish-brown, often in one piece.
- Luster: Silky to vitreous; polished pieces show a moving, rolling chatoyancy.
- Transparency: Opaque.
- Texture: Brecciated — angular fragments of fiber bundles set in a quartz matrix, so the sheen runs in many directions.
Step-by-Step Field ID Checklist
- Tilt it under a light. Genuine pietersite shows chatoyancy (a cat's-eye-like sheen) that shifts direction across the stone, not in one straight band.
- Look for chaos. The fiber bundles point every which way, giving a swirling, smoke-like or storm-cloud appearance.
- Check for brecciation. You should see angular fragments cemented together, sometimes with darker seams.
- Confirm hardness. It scratches glass easily.
- Note the color play. Blue and gold flashes in the same specimen are a strong indicator.
Key Diagnostic Tests
- Mohs hardness: ~6.5–7 (quartz-based). It will scratch glass and resist a steel knife.
- Streak: White to pale grey.
- Fracture: Conchoidal in the silicified matrix; no cleavage.
- Density: ~2.6–2.7 g/cm³, typical of quartz.
- Acid: No reaction (silica, not carbonate).
Common Look-Alikes and How to Tell Them Apart
- Tiger's eye / hawk's eye: These show straight, parallel chatoyant bands. Pietersite's sheen is swirling and multidirectional with brecciation.
- Labradorite/spectrolite: Shows flat schiller flashes tied to crystal faces and is a feldspar (hardness ~6, has cleavage). Pietersite is harder, has no cleavage, and shows fibrous (not flat-plate) play.
- Dyed or reconstituted imitations: Overly uniform, glassy resin-bound pieces with even color lack genuine fibrous chatoyancy; a hot point or acetone test on suspect resin material helps.
- Pietersite vs. tiger iron: Tiger iron pairs tiger's eye with red jasper and magnetic hematite; a magnet may tug tiger iron, and its banding is layered, not chaotic.
Where Pietersite Is Found
The original deposit is in Namibia (near Outjo), discovered by Sid Pieters. A second major source is in Henan Province, China. The Namibian "storm stone" tends toward stronger blues; Chinese material often shows more red and gold.
Frequently asked questions
How can you tell if it's real pietersite?
Genuine pietersite shows swirling, multidirectional chatoyancy and a brecciated texture of angular fiber fragments, with a hardness near 6.5–7 that scratches glass. Uniform, glassy, evenly colored pieces are likely resin imitations.
What does pietersite look like?
It looks like a captured storm: stormy blues, golds, and reddish-browns with a silky sheen that rolls and shifts as you tilt the stone, set in a fragmented, brecciated pattern.
What is the difference between pietersite and tiger's eye?
Tiger's eye has straight parallel bands of golden sheen, while pietersite has chaotic, swirling chatoyancy and a brecciated structure with mixed blue and gold colors.
Where does pietersite come from?
The main sources are Namibia (the original storm-stone deposit) and Henan Province, China.
Pietersite identified by the community
Recent Pietersite specimens identified with Rock Identifier.
