Gramaccioliite-(Y) is a rare mineral belonging to the crichtonite group, typically occurring as small, dark, rhombohedral crystals in pegmatite cavities. It is distinguished by its yttrium content and is usually found in highly specialized geological settings like the famous Baveno granite.
Is this gramaccioliite-(y)?
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 gramaccioliite-(y) with a known reference. Gramaccioliite-(Y) sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Gramaccioliite-(Y) leaves a brownish black streak.
- 3Read the lusterHold the specimen under a strong light. Gramaccioliite-(Y) typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals.
Often confused with
Gramaccioliite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside gramaccioliite-(y)
Minerals reported to co-occur with gramaccioliite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Y,Pb,U)(Ti,Fe³⁺,Fe²⁺)₂₁O₃₈
- Mohs hardness
- 5-6
- Density
- 4.45 g/cm³
- Colors
- Streak
- Brownish Black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $100-500 for small high-quality specimens
Where rockhounds find gramaccioliite-(y)
Classic worldwide localities
- Baveno, Piedmont, Italy
- Mount Malosa, Zomba District, Malawi
Field-hunting tip
Look in granite pegmatites country — that is the host setting where gramaccioliite-(y) typically forms. If you start seeing quartz, microcline, albite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.







