Clinotobermorite is a rare calcium silicate hydrate mineral found primarily in metamorphic skarn environments. It forms as thin, platy or fibrous aggregates and is often distinguished from standard tobermorite by its monoclinic crystal structure. Collectors typically find it as an accessory mineral in complex calcium-silicate assemblages formed through contact metamorphism.

Hardness
4
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this clinotobermorite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch clinotobermorite with a known reference. Clinotobermorite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Clinotobermorite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Clinotobermorite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: white, colorless.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: platy crystals, fibrous, massive.

Often confused with

Clinotobermorite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside clinotobermorite

Minerals reported to co-occur with clinotobermorite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
Ca₅Si₆(O,OH)₁₈·5H₂O
Mohs hardness
4
Density
2.44 g/cm³
Streak
White
Luster
Vitreous
Transparency
Translucent
Crystal system
Monoclinic
Crystal habit
Platy Crystals, Fibrous, Massive
Cleavage
Perfect On {001}
Rarity
Rare
Uses
Collector
Host rock
Skarn Deposits
Typical price
$50-300 per specimen

Where rockhounds find clinotobermorite

Classic worldwide localities

  • Fuka, Okayama Prefecture, Japan
  • Khibiny Massif, Russia
  • Zeilberg, Bavaria, Germany

Field-hunting tip

Look in skarn deposits country — that is the host setting where clinotobermorite typically forms. If you start seeing calcite, afwillite, oyelite in float, you are in the right ground. Field specimens usually show a platy crystals, fibrous, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify clinotobermorite?+
Mohs hardness is 4. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.
Where is clinotobermorite found?+
Notable localities include Fuka, Okayama Prefecture, Japan; Khibiny Massif, Russia; Zeilberg, Bavaria, Germany.
How much is clinotobermorite worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like clinotobermorite?+
Clinotobermorite is most often confused with Tobermorite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with clinotobermorite?+
Clinotobermorite commonly co-occurs with Calcite, Afwillite, Oyelite, Rankinite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does clinotobermorite form in?+
Clinotobermorite typically forms in skarn deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is clinotobermorite used for?+
Clinotobermorite is used in collector.

Find clinotobermorite on the map

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