Grandreefite is a rare lead sulfate-fluoride mineral named after its type locality at the Grand Reef mine in Arizona. It typically forms clear, tabular, adamantine-luster crystals that are often found associated with other lead-bearing minerals in oxidized vein deposits.

Hardness

2.5

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Grandreefite

Hardness: 2.5
Luster: Adamantine
Streak: White
Transparency: Transparent

No image

Is this grandreefite?

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 grandreefite with a known reference. Grandreefite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Grandreefite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Grandreefite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: colorless, white, pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

Often found alongside grandreefite

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

All properties

Chemical formula: Pb₂SO₄F₂
Mohs hardness: 2.5
Density: 6.12 g/cm³
Colors: Colorless White Pale Yellow
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Lead-zinc Veins
Typical price: $50-300 per specimen depending on size and quality

Where rockhounds find grandreefite

Classic worldwide localities

Grand Reef mine, Arizona, USA

Field-hunting tip

Look in oxidized hydrothermal lead-zinc veins country — that is the host setting where grandreefite typically forms. If you start seeing anglesite, lanarkite, cerussite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify grandreefite?+

Mohs hardness is 2.5. It typically shows a adamantine luster. The streak is white. Common colors include colorless, white, pale yellow.

Where is grandreefite found?+

Notable localities include Grand Reef mine, Arizona, USA.

How much is grandreefite worth?+

Typical asking prices fall in the range of $50-300 per specimen depending on size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is grandreefite safe to handle?+

It contains toxic constituents. Contains lead, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust when breaking specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like grandreefite?+

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

What minerals are found with grandreefite?+

Grandreefite commonly co-occurs with anglesite, lanarkite, cerussite, galena. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does grandreefite form in?+

Grandreefite typically forms in oxidized hydrothermal lead-zinc veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is grandreefite used for?+

Grandreefite is used in collector.

Find grandreefite on the map

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