Eirikite is a very rare member of the beryl group, first discovered in the alkaline pegmatites of Greenland. Collectors typically find it as small, clear, hexagonal prisms associated with other rare alkaline minerals in syenite complexes.
Is this eirikite?
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 eirikite with a known reference. Eirikite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to silky.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic crystals.
Often confused with
Eirikite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside eirikite
Minerals reported to co-occur with eirikite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KNa₆Be₂(Si₁₅Al₃)O₃₉F₂
- Mohs hardness
- 6
- Density
- 2.59 g/cm³
- Streak
- White
- Luster
- Vitreous to silky
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Prismatic crystals
- Cleavage
- Good on {101̄0}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A late-stage hydrothermal mineral in a dike of nepheline syenite pegmatite
Where rockhounds find eirikite
Classic worldwide localities
- Vesle Arøy island, Langesundsfjord district, Larvik community, Vestfold county, Norway (type locality)
Field-hunting tip
Where it forms: A late-stage hydrothermal mineral in a dike of nepheline syenite pegmatite. If you start seeing microcline, zircon, aegirine in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify eirikite?+
Where is eirikite found?+
Is eirikite safe to handle?+
What rocks look like eirikite?+
What minerals are found with eirikite?+
What kind of rock does eirikite form in?+
What is eirikite used for?+
Find eirikite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
