Chibaite is a rare variety of quartz characterized by the inclusion of natural gas, specifically methane, within its crystal structure. It is typically found in gas-bearing sedimentary formations where it displays a distinct trapezohedral crystal habit. Collectors prize this mineral for its unique formation history and its specific locality occurrence in Japan.
Is this chibaite?
3-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch chibaite with a known reference. Chibaite sits at Mohs 5.5-7, softer than the next harder reference, harder than the previous one.
- 2Match the color rangeCompare against the expected color range: colorless.
- 3Look at form & habitCrystal system: cubic. Typical habit: trapezohedral crystals.
Often confused with
Chibaite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chibaite
Minerals reported to co-occur with chibaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂·n(CH₄,C₂H₆,C₃H₈,C₄H₁₀) (nₘₐₓ = 3/17)
- Mohs hardness
- 5.5-7
- Density
- 2.03 g/cm³
- Colors
- Transparency
- Transparent to translucent
- Crystal system
- Cubic
- Crystal habit
- Trapezohedral crystals
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As veins cutting tuffaceous sandstone and mudstone in forearc marine sediments deposited near the plate margin of the Paleo-Izu arc and the triple junction of the Pacific, Philippine Sea, and North America plates
Where rockhounds find chibaite
Classic worldwide localities
- Hota Group or Emi Group marine sediments, Arakawa, Minami-boso City, Chiba Prefecture, Japan
Field-hunting tip
Where it forms: As veins cutting tuffaceous sandstone and mudstone in forearc marine sediments deposited near the plate margin of the Paleo-Izu arc and the triple junction of the Pacific, Philippine Sea, and North America plates. If you start seeing doh-type silicate clathrate, calcite, quartz in float, you are in the right ground. Typical habit: trapezohedral crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify chibaite?+
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What rocks look like chibaite?+
What minerals are found with chibaite?+
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Find chibaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
