Manganiandrosite-(La) is an exceptionally rare member of the epidote group found primarily in manganese-rich geological environments. Collectors typically identify it by its dark, opaque, prismatic habit and association with other manganese minerals like braunite and spessartine.
Is this manganiandrosite-(la)?
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 manganiandrosite-(la) with a known reference. Manganiandrosite-(La) sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brownish-gray.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: reddish brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Manganiandrosite-(La) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Manganiandrosite-(La) leaves brownish-gray, Epidote leaves grayish white.
How to tell apart: Streak differs, so Manganiandrosite-(La) leaves brownish-gray, Allanite leaves gray; luster reads vitreous on Manganiandrosite-(La) and submetallic on Allanite.
Often found alongside manganiandrosite-(la)
Minerals reported to co-occur with manganiandrosite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MnLaAlMnMn(Si₂O₇)(SiO₄)O(OH)
- Mohs hardness
- 6-7
- Density
- 4.21 g/cm³
- Colors
- Streak
- Brownish-gray
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Forms a series with piemontite
Where rockhounds find manganiandrosite-(la)
Classic worldwide localities
- Petalon Mountain, Andros Island, Cyclades, Greece (type locality)
Field-hunting tip
Where it forms: Forms a series with piemontite. If you start seeing quartz, braunite, spessartine 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 manganiandrosite-(la)?+
Where is manganiandrosite-(la) found?+
What rocks look like manganiandrosite-(la)?+
What minerals are found with manganiandrosite-(la)?+
What kind of rock does manganiandrosite-(la) form in?+
What is manganiandrosite-(la) used for?+
Find manganiandrosite-(la) on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
