Hogarthite is a rare sodium potassium calcium silicate, typically tan to white to colorless. It was approved as a distinct mineral species in 2009. It was first described from the Poudrette quarry (level 4), Montérégie, Quebec, Canada.
Is this hogarthite?
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 hogarthite with a known reference. Hogarthite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hogarthite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hogarthite typically shows a silky to vitreous luster.
- 4Match the color rangeCompare against the expected color range: tan, white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Hogarthite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hogarthite
Minerals reported to co-occur with hogarthite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,K)₂CaTi₂Si₁₀O₂₆·8H₂O
- Mohs hardness
- 3-4
- Density
- 2.40 g/cm³
- Streak
- White
- Luster
- Silky to Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Igneous Rocks
Where rockhounds find hogarthite
Classic worldwide localities
- Poudrette quarry (level 4), Quebec, Canada
Field-hunting tip
Look in alkaline igneous rocks country, the host setting where hogarthite typically forms. If you start seeing nepheline, aegirine, microcline in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hogarthite?+
Where is hogarthite found?+
What rocks look like hogarthite?+
What minerals are found with hogarthite?+
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Find hogarthite on the map
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