Pseudograndreefite is an extremely rare lead sulfate fluoride mineral found primarily in the oxidation zones of hydrothermal lead deposits. Collectors should look for its characteristic adamantine luster and tabular crystal habit in specimens from the Grand Reef Mine.

Hardness

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Pseudograndreefite

Hardness: 2
Luster: Adamantine
Streak: White
Transparency: Transparent

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Is this pseudograndreefite?

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

Often confused with

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

How to tell apart: Streak differs — Pseudograndreefite leaves white, Linarite leaves pale blue; luster reads adamantine on Pseudograndreefite and vitreous on Linarite.

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Often found alongside pseudograndreefite

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

All properties

Chemical formula: Pb₆SO₄F₁₀
Mohs hardness: 2
Density: 6.57 g/cm³
Colors: Colorless White
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Tabular Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $100-500 thumbnail

Where rockhounds find pseudograndreefite

Classic worldwide localities

Grand Reef Mine, Arizona, USA

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where pseudograndreefite typically forms. If you start seeing grandreefite, galena, anglesite 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 pseudograndreefite?+

Mohs hardness is 2. It typically shows a adamantine luster. The streak is white. Common colors include colorless, white.

Where is pseudograndreefite found?+

Notable localities include Grand Reef Mine, Arizona, USA.

How much is pseudograndreefite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is pseudograndreefite safe to handle?+

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

What rocks look like pseudograndreefite?+

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

What minerals are found with pseudograndreefite?+

Pseudograndreefite commonly co-occurs with Grandreefite, Galena, Anglesite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pseudograndreefite form in?+

Pseudograndreefite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pseudograndreefite used for?+

Pseudograndreefite is used in collector.

Find pseudograndreefite on the map

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