Natromarkeyite is a rare hydrated sodium calcium carbonate mineral discovered in the alkaline rocks of Mont Saint-Hilaire. Collectors should look for its distinctive platy or prismatic crystal habits occurring within cavities of intrusive igneous rocks. It is highly sensitive to humidity and should be stored in a controlled environment to prevent dehydration.
Is this natromarkeyite?
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 natromarkeyite with a known reference. Natromarkeyite sits at Mohs 2.5-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Natromarkeyite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Natromarkeyite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white, yellowish.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy to prismatic crystals.
Often confused with
Natromarkeyite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside natromarkeyite
Minerals reported to co-occur with natromarkeyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Ca(CO₃)₂·5H₂O
- Mohs hardness
- 2.5-3
- Density
- 2.83 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy to Prismatic Crystals
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Igneous Rocks
- Typical price
- $50-500 depending on specimen quality
Where rockhounds find natromarkeyite
Classic worldwide localities
- Mont Saint-Hilaire (Canada)
Field-hunting tip
Look in alkaline igneous rocks country — that is the host setting where natromarkeyite typically forms. If you start seeing dawsonite, siderite, analcime in float, you are in the right ground. Field specimens usually show a platy to prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify natromarkeyite?+
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Find natromarkeyite on the map
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