Ewaldite is a rare carbonate mineral typically found in complex alkaline igneous environments. Collectors look for its characteristic platy, pseudohexagonal crystals, often associated with other rare earth minerals like mckelveyite.
Is this ewaldite?
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 ewaldite with a known reference. Ewaldite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: white, bluish green, greenish gray.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: prismatic.
Often confused with
Ewaldite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ewaldite
Minerals reported to co-occur with ewaldite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- BaCa(CO₃)₂·2.6H₂O
- Mohs hardness
- 3.5
- Density
- 3.25 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Hexagonal
- Crystal habit
- Prismatic
- Cleavage
- None
- Fluorescence
- Bright white to pale yellow under UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- From drill core into trona beds in dolomitic marlstone (Green River Formation, Wyoming, USA); from carbonatites and hydrothermal veins in alkaline igneous rocks (Kola Peninsula, Russia)
Where rockhounds find ewaldite
Classic worldwide localities
- Green River Formation, Sweetwater Co., Wyoming, USA
- Mont Saint-Hilaire, Quebec, Canada
- Vuoriyarvi carbonatite complex and the Khibiny massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: From drill core into trona beds in dolomitic marlstone (Green River Formation, Wyoming, USA); from carbonatites and hydrothermal veins in alkaline igneous rocks (Kola Peninsula, Russia). If you start seeing mckelveyite-, shortite, labuntsovite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ewaldite?+
Where is ewaldite found?+
What rocks look like ewaldite?+
What minerals are found with ewaldite?+
What kind of rock does ewaldite form in?+
What is ewaldite used for?+
Find ewaldite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
