Adrianite is a rare member of the garnet group typically found in contact metamorphic rocks such as skarns. Collectors should look for its characteristic dodecahedral habit and deep reddish-brown coloration, which helps distinguish it from more common garnets.

Hardness

6.5-7.5

Mohs

Transparency

Transparent

mineralrareGarnet Group family

Adrianite

Hardness: 6.5-7.5
Transparency: Transparent

No image

Is this adrianite?

2-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 adrianite with a known reference. Adrianite sits at Mohs 6.5-7.5, softer than the next harder reference, harder than the previous one.
2
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals.

Often confused with

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

Often found alongside adrianite

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

All properties

Chemical formula: Ca₁₂(Al₄Mg₃Si₇)O₃₂Cl₆
Mohs hardness: 6.5-7.5
Density: 3.03 g/cm³
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Dodecahedral crystals
Rarity: Rare
Uses: Collector
Host rock: In altered areas along veins between primary melilite, spinel, and Ti-Al-diopside in a Type B1 FUN (Fractionation and Unidentified Nuclear effects) Ca-Al-rich inclusion (CAI), Egg-3

Where rockhounds find adrianite

Classic worldwide localities

Allende CV3 carbonaceous chondrite, which fell at Pueblito de Allende, Chihuahua, Mexico, on February 8, 1969

Field-hunting tip

Where it forms: In altered areas along veins between primary melilite, spinel, and Ti-Al-diopside in a Type B1 FUN (Fractionation and Unidentified Nuclear effects) Ca-Al-rich inclusion (CAI), Egg-3. If you start seeing monticellite, grossular, wadalite in float, you are in the right ground. Typical habit: dodecahedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify adrianite?+

Mohs hardness is 6.5-7.5.

Where is adrianite found?+

Notable localities include Allende CV3 carbonaceous chondrite, which fell at Pueblito de Allende, Chihuahua, Mexico, on February 8, 1969.

What rocks look like adrianite?+

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

What minerals are found with adrianite?+

Adrianite commonly co-occurs with Monticellite, Grossular, Wadalite, Hutcheonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does adrianite form in?+

Where it forms: In altered areas along veins between primary melilite, spinel, and Ti-Al-diopside in a Type B1 FUN (Fractionation and Unidentified Nuclear effects) Ca-Al-rich inclusion (CAI), Egg-3. Working float back to the host body is the standard way to chase a fresh occurrence.

What is adrianite used for?+

Adrianite is used in collector.

Find adrianite on the map

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