Pertlikite is a very rare member of the garnet group specifically occurring as a secondary mineral in volcanic cavities. Collectors typically find it as small, yellowish-brown dodecahedral crystals associated with quartz and calcite within basaltic host rocks.

Hardness

7-7.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGarnet Group family

Pertlikite

Hardness: 7-7.5
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this pertlikite?

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 pertlikite with a known reference. Pertlikite sits at Mohs 7-7.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Pertlikite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Pertlikite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown.
5
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals.

Often confused with

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

Often found alongside pertlikite

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

All properties

Chemical formula: Ca₂(Fe³⁺,Mg,Mn²⁺)₂(Si,Al)₃O₁₂(OH)₄
Mohs hardness: 7-7.5
Density: 3.55 g/cm³
Colors: Yellow Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Dodecahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Amygdaloidal Basalt Cavities
Typical price: $50-300 per specimen

Where rockhounds find pertlikite

Classic worldwide localities

Kozákov, Czech Republic

Field-hunting tip

Look in amygdaloidal basalt cavities country — that is the host setting where pertlikite typically forms. If you start seeing quartz, calcite, hematite in float, you are in the right ground. Field specimens usually show a dodecahedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pertlikite?+

Mohs hardness is 7-7.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brown.

Where is pertlikite found?+

Notable localities include Kozákov, Czech Republic.

How much is pertlikite 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 pertlikite?+

Pertlikite is most often confused with Grossularite Garnet, Andradite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with pertlikite?+

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

What kind of rock does pertlikite form in?+

Pertlikite typically forms in amygdaloidal basalt cavities. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pertlikite used for?+

Pertlikite is used in collector.

Find pertlikite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.