Oftedalite is a rare scandium-bearing silicate mineral belonging to the sugilite group. It is primarily found as small, colorless to white prismatic crystals in the alkaline rocks of the Poudrette Quarry in Canada.
Is this oftedalite?
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 oftedalite with a known reference. Oftedalite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: colorless.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: grayish white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: hexagonal, prismatic.
Often confused with
Oftedalite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside oftedalite
Minerals reported to co-occur with oftedalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K(ScCa)□₂Be₃Si₁₂O₃₀
- Mohs hardness
- 6
- Density
- 2.61 g/cm³
- Colors
- Streak
- Colorless
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Hexagonal
- Crystal habit
- Hexagonal, prismatic
- Cleavage
- Poor on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a complex granitic pegmatite
Where rockhounds find oftedalite
Classic worldwide localities
- Heftetjern pegmatite, ~ 4.3 km NW of Tørdal, Telemark county, southern Norway
Field-hunting tip
Where it forms: In a complex granitic pegmatite. If you start seeing sc-rich milarite, tourmaline, yttrian milarite in float, you are in the right ground. Typical habit: hexagonal, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify oftedalite?+
Where is oftedalite found?+
Is oftedalite safe to handle?+
What rocks look like oftedalite?+
What minerals are found with oftedalite?+
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Find oftedalite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
