Odinite is a rare member of the chlorite group that typically forms as extremely fine-grained, earthy coatings or aggregates within sedimentary environments. It is most notable for its distinct green to greenish-blue color, often associated with iron-rich marine sediments. Because it is rarely found in macroscopic crystals, it is primarily sought after by advanced mineral collectors and those interested in clay mineralogy.
Is this odinite?
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 odinite with a known reference. Odinite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray-green.
- 3Read the lusterHold the specimen under a strong light. Luster: silky to earthy.
- 4Match the color rangeCompare against the expected color range: green, dark green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: cryptocrystalline.
Often confused with
Odinite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Odinite leaves gray-green, Chlorite leaves white; luster reads silky to earthy on Odinite and pearly on Chlorite.
How to tell apart: Streak differs, so Odinite leaves gray-green, Glauconite leaves light green; luster reads silky to earthy on Odinite and dull, glistening on Glauconite.
How to tell apart: Streak differs, so Odinite leaves gray-green, Chamosite leaves green to gray; luster reads silky to earthy on Odinite and pearly on Chamosite.
Often found alongside odinite
Minerals reported to co-occur with odinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe³⁺,Mg,Al,Fe²⁺)₆(Si,Al)₄O₁₀(OH,O)₈
- Mohs hardness
- 2.5
- Density
- 2.6 g/cm³
- Colors
- Streak
- Gray-green
- Luster
- Silky to earthy
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Cryptocrystalline
- Cleavage
- Perfect basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Formed in marine waters, a minor component of green clay infillings or replacements of microtests, bioclasts, fecal pellets, or mineral debris on shallow marine shelfs and reef lagoonal areas in tropical latitudes
Where rockhounds find odinite
Classic worldwide localities
- Among these are the reef lagoon southwest of New Caledonia
- Ogooue River prodelta, Congo Republic
- Continental shelf between the Amazon and Orinoco Rivers, Brazil
- Niger River prodelta, Nigeria
- Los Islands, in the mouth of the Koukoure River, Guinea
Field-hunting tip
Where it forms: Formed in marine waters, a minor component of green clay infillings or replacements of microtests, bioclasts, fecal pellets, or mineral debris on shallow marine shelfs and reef lagoonal areas in tropical latitudes. If you start seeing quartz, calcite, kaolinite in float, you are in the right ground. Typical habit: cryptocrystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify odinite?+
Where is odinite found?+
What rocks look like odinite?+
What minerals are found with odinite?+
What kind of rock does odinite form in?+
What is odinite used for?+
Find odinite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
