Dumortierite Quartz is a popular lapidary material characterized by dense inclusions of fibrous blue dumortierite needles trapped within a clear or milky quartz host. It is easily identified by its distinctive denim-blue color and typical massive habit, making it a favorite for carving and jewelry.
Is this dumortierite quartz?
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 dumortierite quartz with a known reference. Dumortierite Quartz 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. Dumortierite Quartz leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Dumortierite Quartz typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, violet-blue, deep blue.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive.
Often confused with
Dumortierite Quartz vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Dumortierite Quartz is noticeably harder (Mohs 7 vs. 5.5-6).
How to tell apart: Dumortierite Quartz is noticeably harder (Mohs 7 vs. 5-5.5); streak differs — Dumortierite Quartz leaves white, Lazurite leaves light blue.
How to tell apart: Luster reads vitreous on Dumortierite Quartz and waxy on Blue Chalcedony.
Often found alongside dumortierite quartz
Minerals reported to co-occur with dumortierite quartz. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 7
- Density
- 2.65 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Hydrothermal Veins and Pegmatites
- Typical price
- $5-50 for cabochons or rough specimens
Where rockhounds find dumortierite quartz
Classic worldwide localities
- Namibia
- Brazil
- Madagascar
- USA
- Peru
Field-hunting tip
Look in hydrothermal veins and pegmatites country — that is the host setting where dumortierite quartz typically forms. If you start seeing quartz, dumortierite, muscovite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify dumortierite quartz?+
Where is dumortierite quartz found?+
How much is dumortierite quartz worth?+
What rocks look like dumortierite quartz?+
What minerals are found with dumortierite quartz?+
What kind of rock does dumortierite quartz form in?+
What is dumortierite quartz used for?+
Find dumortierite quartz on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
