Neotocite is an amorphous, manganese-rich silicate mineral that typically forms as a secondary alteration product in manganese deposits. It is easily identified by its dark, often black or brown color and glass-like luster, appearing in massive or botryoidal habit rather than distinct crystals.
Is this neotocite?
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 neotocite with a known reference. Neotocite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Neotocite leaves a brown streak.
- 3Read the lusterHold the specimen under a strong light. Neotocite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, dark brown, reddish-brown.
- 5Look at form & habitTypical habit: amorphous, botryoidal, crusts, massive.
Often confused with
Neotocite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Romanèchite is the harder of the two (Mohs 5-6 vs. 3-4); streak differs, so Neotocite leaves brown, Romanèchite leaves shiny brownish black; luster reads vitreous on Neotocite and submetallic to dull on Romanèchite.
How to tell apart: Streak differs, so Neotocite leaves brown, Limonite leaves yellowish-brown; luster reads vitreous on Neotocite and submetallic to earthy on Limonite.
How to tell apart: Rhodonite is the harder of the two (Mohs 5.5-6.5 vs. 3-4); streak differs, so Neotocite leaves brown, Rhodonite leaves white.
Often found alongside neotocite
Minerals reported to co-occur with neotocite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mn,Fe)SiO₃·nH₂O
- Mohs hardness
- 3-4
- Density
- 2.7-3.0 g/cm³
- Streak
- Brown
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal habit
- Amorphous, Botryoidal, Crusts, Massive
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Hydrothermal Veins, Manganese Ore Deposits
- Typical price
- $10-50 per specimen
Where rockhounds find neotocite
2 mapped spotsClassic worldwide localities
- Sweden
- Germany
- Czech Republic
- USA
- Japan
Field-hunting tip
Look in hydrothermal veins, manganese ore deposits country, the host setting where neotocite typically forms. If you start seeing rhodochrosite, rhodonite, quartz in float, you are in the right ground. Field specimens usually show a amorphous, botryoidal, crusts, massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California. Start trip planning there.
Common questions
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Find neotocite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
