Magnesiochloritoid is a rare member of the chloritoid group found in high-pressure, low-temperature metamorphic environments. It typically appears as dark, tabular or platy crystals embedded within schistose host rocks, often requiring microscopic examination for positive identification.
Is this magnesiochloritoid?
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 magnesiochloritoid with a known reference. Magnesiochloritoid sits at Mohs 6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Magnesiochloritoid leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Magnesiochloritoid typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: dark green, black, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, foliated masses, rosettes.
Often confused with
Magnesiochloritoid vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads pearly on Magnesiochloritoid and vitreous on Ottrélite.
How to tell apart: Magnesiochloritoid is noticeably harder (Mohs 6.5 vs. 2-3).
How to tell apart: Luster reads pearly on Magnesiochloritoid and vitreous to resinous on Staurolite.
Often found alongside magnesiochloritoid
Minerals reported to co-occur with magnesiochloritoid. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgAl₂SiO₅(OH)₂
- Mohs hardness
- 6.5
- Density
- 3.5-3.6 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Foliated Masses, Rosettes
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks
- Typical price
- $20-100 per specimen
Where rockhounds find magnesiochloritoid
Classic worldwide localities
- Greece
- Italy
- Spain
- Japan
Field-hunting tip
Look in metamorphic rocks country, the host setting where magnesiochloritoid typically forms. If you start seeing quartz, muscovite, chlorite in float, you are in the right ground. Field specimens usually show a tabular crystals, foliated masses, rosettes habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify magnesiochloritoid?+
Where is magnesiochloritoid found?+
How much is magnesiochloritoid worth?+
What rocks look like magnesiochloritoid?+
What minerals are found with magnesiochloritoid?+
What kind of rock does magnesiochloritoid form in?+
What is magnesiochloritoid used for?+
Find magnesiochloritoid on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
