Merlinoite is a rare member of the zeolite group that typically occurs as small, clear, pseudo-cubic crystals within volcanic vesicles. It is chemically similar to phillipsite but is distinguished by its specific orthorhombic symmetry and diffraction patterns. It is highly sought after by micromount collectors due to its restricted occurrence in specific volcanic environments.
Is this merlinoite?
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 merlinoite with a known reference. Merlinoite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Merlinoite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Merlinoite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: equant pseudo-cubic crystals.
Often confused with
Merlinoite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside merlinoite
Minerals reported to co-occur with merlinoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (K,Na,Ca)₈(Si,Al)₃₂O₆₄·24H₂O
- Mohs hardness
- 4
- Density
- 2.12 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Equant Pseudo-cubic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Rocks
- Typical price
- $20-150 for micro-mounts or small thumbnails
Where rockhounds find merlinoite
Classic worldwide localities
- Cupola Mountain, California, USA
- Vesuvius, Italy
- Giara di Gesturi, Sardinia, Italy
- Khibiny Massif, Russia
Field-hunting tip
Look in volcanic rocks country — that is the host setting where merlinoite typically forms. If you start seeing phillipsite, calcite, chabazite in float, you are in the right ground. Field specimens usually show a equant pseudo-cubic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify merlinoite?+
Where is merlinoite found?+
How much is merlinoite worth?+
What rocks look like merlinoite?+
What minerals are found with merlinoite?+
What kind of rock does merlinoite form in?+
What is merlinoite used for?+
Find merlinoite on the map
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