Magnesiodumortierite is a rare magnesium-dominant analogue of the standard dumortierite species, characterized by its vibrant blue to violet coloration. It typically occurs as fibrous aggregates or massive veins within aluminum-rich metamorphic environments such as pelitic schists and gneisses.
Is this magnesiodumortierite?
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 magnesiodumortierite with a known reference. Magnesiodumortierite sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Magnesiodumortierite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Magnesiodumortierite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, violet, pink, brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: fibrous, columnar, or massive.
Often confused with
Magnesiodumortierite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside magnesiodumortierite
Minerals reported to co-occur with magnesiodumortierite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgAl₆BSi₃O₁₈(OH)
- Mohs hardness
- 7
- Density
- 3.3-3.4 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Fibrous, Columnar, Or Massive
- Cleavage
- Distinct in One Direction
- Rarity
- Rare
- Uses
- Collector, Lapidary
- Host rock
- Aluminum-rich Metamorphic Rocks
- Typical price
- $20-200 depending on specimen size and clarity
Where rockhounds find magnesiodumortierite
Classic worldwide localities
- Madagascar
- Mozambique
- Austria
- Brazil
Field-hunting tip
Look in aluminum-rich metamorphic rocks country — that is the host setting where magnesiodumortierite typically forms. If you start seeing quartz, kyanite, garnet in float, you are in the right ground. Field specimens usually show a fibrous, columnar, or massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify magnesiodumortierite?+
Where is magnesiodumortierite found?+
How much is magnesiodumortierite worth?+
What rocks look like magnesiodumortierite?+
What minerals are found with magnesiodumortierite?+
What kind of rock does magnesiodumortierite form in?+
What is magnesiodumortierite used for?+
Find magnesiodumortierite on the map
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