Creedite is a highly sought-after mineral by collectors due to its vibrant orange to purple prismatic crystals and striking radial sprays. It typically forms in the oxidation zones of ore deposits and is famous for its intense fluorescence under ultraviolet light.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineraluncommon

Creedite

Hardness: 4
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

Is this creedite?

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 creedite with a known reference. Creedite 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. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: colorless, violet, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: granular, prismatic, radial.

Often confused with

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

Often found alongside creedite

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

All properties

Chemical formula: Ca₃Al₂(SO₄)(OH)₂F₈·2H₂O
Mohs hardness: 4
Density: 2.713-2.730 g/cm³
Colors: Colorless Violet White
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Granular, prismatic, radial
Cleavage: {100}, perfect
Rarity: Uncommon
Uses: Collector
Host rock: Uncommon in fluorite-rich hydrothermal mineral deposits

Where rockhounds find creedite

Classic worldwide localities

Wagon Wheel Gap, near Creede, Mineral Co., Colorado, USA
Liberty and Hall mines and at Granite, near Tonopah, Nye Co., Nevada, USA
Grand Reef mine, Graham Co., Arizona, USA
Thompson and Defiance mines, Darwin district, Inyo Co., California, USA
Potosí and other mines, Santa Eulalia district, Chihuahua, Mexico
Colquiri, La Paz, Bolivia

Field-hunting tip

Where it forms: Uncommon in fluorite-rich hydrothermal mineral deposits. If you start seeing fluorite, barite, kaolinite in float, you are in the right ground. Typical habit: granular, prismatic, radial. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify creedite?+

Mohs hardness is 4. Luster: vitreous. The streak is white. Common colors include colorless, violet, white.

Where is creedite found?+

Notable localities include Wagon Wheel Gap, near Creede, Mineral Co., Colorado, USA; Liberty and Hall mines and at Granite, near Tonopah, Nye Co., Nevada, USA; Grand Reef mine, Graham Co., Arizona, USA; Thompson and Defiance mines, Darwin district, Inyo Co., California, USA; Potosí and other mines, Santa Eulalia district, Chihuahua, Mexico.

What rocks look like creedite?+

Creedite is most often confused with Stilbite, Heulandite, Apophyllite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with creedite?+

Creedite commonly co-occurs with Fluorite, Barite, Kaolinite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does creedite form in?+

Where it forms: Uncommon in fluorite-rich hydrothermal mineral deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is creedite used for?+

Creedite is used in collector.

Find creedite on the map

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