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

No image

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, 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.