Florencite-(Sm) is a rare rare-earth element phosphate mineral belonging to the beudantite group. It typically occurs as small rhombohedral crystals in hydrothermal deposits and altered metamorphic rocks, and can be visually indistinguishable from other members of the florencite series without analytical testing.

Hardness

5.5-6

Mohs

Luster

Vitreous to greasy

Streak

White

Transparency

Transparent

mineralrareFlorencite Group family

Florencite-(Sm)

Hardness: 5.5-6
Luster: Vitreous to greasy
Streak: White
Transparency: Transparent

No image

Is this florencite-(sm)?

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 florencite-(sm) with a known reference. Florencite-(Sm) sits at Mohs 5.5-6, 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 to greasy.
4
Match the color range
Compare against the expected color range: colorless, pale pink, pale yellow.
5
Look at form & habit
Crystal system: trigonal. Typical habit: rhombohedral crystals.

Often confused with

Florencite-(Sm) vs. its common look-alikes, and how to tell them apart in the field.

mineral

Florencite-(Ce)

Mohs 5-6

How to tell apart: Luster reads vitreous to greasy on Florencite-(Sm) and greasy to resinous on Florencite-(Ce).

How to tell apart: Luster reads vitreous to greasy on Florencite-(Sm) and greasy to resinous on Florencite-(La).

Often found alongside florencite-(sm)

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

All properties

Chemical formula: SmAl₃(PO₄)₂(OH)₆
Mohs hardness: 5.5-6
Density: 3.60 g/cm³
Colors: Colorless Pale pink Pale yellow
Streak: White
Luster: Vitreous to greasy
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Rhombohedral crystals
Cleavage: Perfect on {0001}; parting on {112̄0}
Rarity: Rare
Uses: Collector
Host rock: In quartz veins cutting quartz meta-conglomerate beds near contacts with Al-enriched metasomatites

Where rockhounds find florencite-(sm)

Classic worldwide localities

Svodovyi site, Maldynyrd Ridge, Subpolar Urals, Russia

Field-hunting tip

Where it forms: In quartz veins cutting quartz meta-conglomerate beds near contacts with Al-enriched metasomatites. If you start seeing florencite-, xenotime-, quartz in float, you are in the right ground. Typical habit: rhombohedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify florencite-(sm)?+

Mohs hardness is 5.5-6. Luster: vitreous to greasy. The streak is white. Common colors include colorless, pale pink, pale yellow.

Where is florencite-(sm) found?+

Notable localities include Svodovyi site, Maldynyrd Ridge, Subpolar Urals, Russia.

What rocks look like florencite-(sm)?+

Florencite-(Sm) is most often confused with Florencite-(Ce), Florencite-(La), Crandallite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with florencite-(sm)?+

Florencite-(Sm) commonly co-occurs with Florencite-, Xenotime-, Quartz, Dravite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does florencite-(sm) form in?+

Where it forms: In quartz veins cutting quartz meta-conglomerate beds near contacts with Al-enriched metasomatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is florencite-(sm) used for?+

Florencite-(Sm) is used in collector.

Find florencite-(sm) on the map

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