Semenovite-(Ce) is a rare beryllium-bearing silicate mineral primarily found in hyper-alkaline igneous complexes. It typically appears as yellowish-brown to black anhedral masses or tabular crystals associated with other rare earth elements and alkaline minerals.
Is this semenovite-(ce)?
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 semenovite-(ce) with a known reference. Semenovite-(Ce) sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellowish-white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, to dull when altered.
- 4Match the color rangeCompare against the expected color range: brown, orange-brown, gray, reddish brown when altered.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular to equant crystals, often found as anhedral grains or granular aggregates.
Often confused with
Semenovite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Eudialyte is the harder of the two (Mohs 5-6 vs. 3.5-4); streak differs, so Semenovite-(Ce) leaves yellowish-white, Eudialyte leaves white.
How to tell apart: Streak differs, so Semenovite-(Ce) leaves yellowish-white, Steenstrupine-(Ce) leaves brownish, nearly white; luster reads vitreous, to dull when altered on Semenovite-(Ce) and dull on Steenstrupine-(Ce).
Often found alongside semenovite-(ce)
Minerals reported to co-occur with semenovite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca)₉FeCe₂(Si,Be)₂₀(O,OH,F)₄₈
- Mohs hardness
- 3.5-4
- Density
- 3.140 g/cm³
- Colors
- Streak
- Yellowish-white
- Luster
- Vitreous, to dull when altered
- Transparency
- Transparent, to translucent when altered
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular to equant crystals, often found as anhedral grains or granular aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A late-stage hydrothermal mineral developed in cavities within albitite veins cutting alkalic igneous rocks
Where rockhounds find semenovite-(ce)
Classic worldwide localities
- Ilimaussaq complex, Greenland
- Khibiny Massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: A late-stage hydrothermal mineral developed in cavities within albitite veins cutting alkalic igneous rocks. If you start seeing epididymite, eudidymite, lithium-mica in float, you are in the right ground. Typical habit: tabular to equant crystals, often found as anhedral grains or granular aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify semenovite-(ce)?+
Where is semenovite-(ce) found?+
Is semenovite-(ce) safe to handle?+
What rocks look like semenovite-(ce)?+
What minerals are found with semenovite-(ce)?+
What kind of rock does semenovite-(ce) form in?+
What is semenovite-(ce) used for?+
Find semenovite-(ce) on the map
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