Umbrianite is an exceptionally rare sodium silicate mineral found primarily within the ejecta of the Somma-Vesuvius volcanic complex. Collectors usually encounter it as small, colorless to pale yellow tabular crystals embedded in volcanic matrices.
Is this umbrianite?
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 umbrianite with a known reference. Umbrianite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Umbrianite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Umbrianite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white, yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals.
Often confused with
Umbrianite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside umbrianite
Minerals reported to co-occur with umbrianite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₈(Si₆O₁₈)Cl₂
- Mohs hardness
- 3.5
- Density
- 2.81 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Ejecta
- Typical price
- $50-300 per specimen
Where rockhounds find umbrianite
Classic worldwide localities
- Vesuvius, Italy
- Somma-Vesuvius complex, Italy
Field-hunting tip
Look in volcanic ejecta country — that is the host setting where umbrianite typically forms. If you start seeing phlogopite, fluorite, sodalite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify umbrianite?+
Where is umbrianite found?+
How much is umbrianite worth?+
What rocks look like umbrianite?+
What minerals are found with umbrianite?+
What kind of rock does umbrianite form in?+
What is umbrianite used for?+
Find umbrianite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
