Fluorellestadite is a rare member of the apatite group characterized by significant silicon and sulfur substitution. It is primarily known for its distinct fluorescent properties, often glowing brilliantly under ultraviolet light. Collectors typically find it in contact-metamorphosed limestone or skarn deposits associated with calc-silicate minerals.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareApatite Group family

Fluorellestadite

Hardness: 5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this fluorellestadite?

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

Often confused with

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

Often found alongside fluorellestadite

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

All properties

Chemical formula: Ca₅(SiO₄,PO₄,SO₄)₃(F,OH,Cl)
Mohs hardness: 5
Density: 3.1-3.2 g/cm³
Colors: White Colorless Yellow Violet
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Hexagonal
Crystal habit: Prismatic Crystals, Massive, Granular
Cleavage: Poor
Fluorescence: Strong Violet or Orange-yellow Under UV
Rarity: Rare
Uses: Collector
Host rock: Contact Metamorphic Rocks and Skarns
Typical price: $20-150 per specimen depending on crystal size and provenance

Where rockhounds find fluorellestadite

Classic worldwide localities

Kopeysk, Chelyabinsk Oblast, Russia
Khibiny Massif, Kola Peninsula, Russia
Franklin, New Jersey, USA
Velardeña, Durango, Mexico

Field-hunting tip

Look in contact metamorphic rocks and skarns country — that is the host setting where fluorellestadite typically forms. If you start seeing calcite, diopside, grossular in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify fluorellestadite?+

Mohs hardness is 5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless, yellow, violet.

Where is fluorellestadite found?+

Notable localities include Kopeysk, Chelyabinsk Oblast, Russia; Khibiny Massif, Kola Peninsula, Russia; Franklin, New Jersey, USA; Velardeña, Durango, Mexico.

How much is fluorellestadite worth?+

Typical asking prices fall in the range of $20-150 per specimen depending on crystal size and provenance. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like fluorellestadite?+

Fluorellestadite is most often confused with Apatite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with fluorellestadite?+

Fluorellestadite commonly co-occurs with Calcite, Diopside, Grossular, Vesuvianite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fluorellestadite form in?+

Fluorellestadite typically forms in contact metamorphic rocks and skarns. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fluorellestadite used for?+

Fluorellestadite is used in collector.

Find fluorellestadite on the map

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