Tiptopite is an extremely rare phosphate mineral known primarily from the Tip Top mine in the Black Hills of South Dakota. It typically forms delicate, needle-like crystals that appear in radiating sprays within phosphate-rich pegmatites.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Tiptopite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this tiptopite?

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 tiptopite with a known reference. Tiptopite sits at Mohs 3.5, 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.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: acicular, radial.

Often confused with

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

mineral

Beryllonite

Mohs 5.5-6

How to tell apart: Beryllonite is the harder of the two (Mohs 5.5-6 vs. 3.5).

How to tell apart: Hurlbutite is the harder of the two (Mohs 6 vs. 3.5).

Compare →

Often found alongside tiptopite

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

All properties

Chemical formula: K₂(Li,Na,Ca)₆(Be₆P₆)O₂₄(OH)₂·1.3H₂O
Mohs hardness: 3.5
Density: 2.65 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Acicular, radial
Cleavage: None
Fluorescence: Bright yellow under SW UV
Rarity: Rare
Uses: Collector
Host rock: On fracture surfaces in earlier minerals in a complex zoned granite pegmatite

Where rockhounds find tiptopite

Classic worldwide localities

Tip Top mine, about 8.5 km southwest of Custer, Custer Co., South Dakota, USA

Field-hunting tip

Where it forms: On fracture surfaces in earlier minerals in a complex zoned granite pegmatite. If you start seeing roscherite, fransoletite, montgomeryite in float, you are in the right ground. Typical habit: acicular, radial. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tiptopite?+

Mohs hardness is 3.5. Luster: vitreous. The streak is white. Common colors include colorless.

Where is tiptopite found?+

Notable localities include Tip Top mine, about 8.5 km southwest of Custer, Custer Co., South Dakota, USA.

Is tiptopite safe to handle?+

Tiptopite contains beryllium. Contains beryllium, which is toxic if inhaled as dust or ingested. Handle specimens with care to avoid creating powder.

What rocks look like tiptopite?+

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

What minerals are found with tiptopite?+

Tiptopite commonly co-occurs with Roscherite, Fransoletite, Montgomeryite, Englishite, Beryl, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tiptopite form in?+

Where it forms: On fracture surfaces in earlier minerals in a complex zoned granite pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tiptopite used for?+

Tiptopite is used in collector.

Find tiptopite on the map

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