Melanophlogite is a rare, silica-based mineral that crystallizes in the cubic system, which is unusual for common SiO₂ species. Collectors prize it for its sharp, small cube-like crystals and distinct, bright blue-white fluorescence under short-wave ultraviolet light.
Is this melanophlogite?
5-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 melanophlogite with a known reference. Melanophlogite sits at Mohs 6-6.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Melanophlogite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Melanophlogite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white, yellow, brown.
- 5Look at form & habitCrystal system: cubic. Typical habit: pseudocubic crystals, cube-like, pyritohedral faces.
Often confused with
Melanophlogite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside melanophlogite
Minerals reported to co-occur with melanophlogite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6-6.5
- Density
- 2.0-2.1 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Pseudocubic Crystals, Cube-like, Pyritohedral Faces
- Cleavage
- None
- Fluorescence
- Bright Blue-white Under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Sulfur-bearing Gypsum or Clay Deposits
- Typical price
- $50-500 depending on specimen size and clarity
Where rockhounds find melanophlogite
Classic worldwide localities
- Fortullino, Italy
- Santa Barbara County, California, USA
- Mount Hamilton, California, USA
- Mezzano, Italy
Field-hunting tip
Look in sulfur-bearing gypsum or clay deposits country — that is the host setting where melanophlogite typically forms. If you start seeing sulfur, calcite, gypsum in float, you are in the right ground. Field specimens usually show a pseudocubic crystals, cube-like, pyritohedral faces habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify melanophlogite?+
Where is melanophlogite found?+
How much is melanophlogite worth?+
What rocks look like melanophlogite?+
What minerals are found with melanophlogite?+
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Find melanophlogite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
