Jarandolite is a very rare calcium borate mineral known primarily from its type locality in Spain. It typically forms as delicate, white bladed crystals or radial clusters and is highly sought after by systematic mineral collectors.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Jarandolite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this jarandolite?

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 jarandolite with a known reference. Jarandolite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Jarandolite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Jarandolite 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: bladed crystals, radial aggregates.

Often confused with

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

mineral

Borax

Mohs 2-2.5

How to tell apart: Jarandolite is noticeably harder (Mohs 3.5 vs. 2-2.5); luster reads vitreous on Jarandolite and vitreous to earthy on Borax.

How to tell apart: Luster reads vitreous on Jarandolite and dull on Priceite.

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Often found alongside jarandolite

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

All properties

Chemical formula: CaHB₇O₁₂
Mohs hardness: 3.5
Density: 2.66 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Bladed Crystals, Radial Aggregates
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find jarandolite

Classic worldwide localities

Jarandola, Spain

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where jarandolite typically forms. If you start seeing calcite, gypsum in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify jarandolite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.

Where is jarandolite found?+

Notable localities include Jarandola, Spain.

How much is jarandolite 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 jarandolite?+

Jarandolite is most often confused with Borax, Priceite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with jarandolite?+

Jarandolite commonly co-occurs with Calcite, Gypsum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does jarandolite form in?+

Jarandolite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is jarandolite used for?+

Jarandolite is used in collector.

Find jarandolite on the map

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