Name/Title
FluorapatiteEntry/Object ID
2009.62.123(b)Description
Chemical Composition: fluorinated calcium phosp
Crystal System: Hexagonal System
Description: Common Name: Fluorapatite
Chemistry: Ca5(PO4)3F
Group: Phosphates
Location: Sludjanka, Baikal, Russia
Description: Three specimens with similar characteristics. All are a light green to emerald green to dark blue in color with a columnar hexagonal shape and translucent in appearance.
Physical Characteristics:
{0001} Indistinct
Color: Blue, Brown, Colorless, Violet, Green.
Density: 3.1 - 3.2, Average = 3.15
Diaphaneity: Transparent to Opaque
Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Hardness: 5 - Apatite
Luminescence: Fluorescent and phosphorescent.
Luster: Vitreous - Resinous
Streak: white
rectangle shape with a greenish yellow color
Ca5(PO4)3F
Color Sea-green, violet, purple, blue, pink, yellow, brown, white, colorless, may be zoned
Crystal habit Massive to prismatic cyrstaliine
Crystal system Hexagonal - dipyramidal
Twinning Contact twins rare
Cleavage Indistinct
Fracture Brittle to conchoidal
Mohs scale hardness 5
Luster Vitreous, resinous to dull
Streak White
Specific gravity 3.1 to 3.2
Optical properties Uniaxial (-)
Refractive index n? = 1.631 - 1.650 ne = 1.633 - 1.646
Birefringence d = 0.002
Ultraviolet fluorescence Fluorescent and phosphorescent.
Fracture: conchoidal
Hardness: 5 Apatite
Luster: Vitreous
Occurrence: Fluorapatite, often with the alternate spelling of fluoroapatite, is a mineral with the formula Ca5(PO4)3F (calcium halophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blue, violet, or colorless), the pure mineral is colorless as expected for a material lacking transition metals. It is an important constituent of tooth enamel.[4]
Fluorapatite crystallizes in a hexagonal crystal system. It is often combined as a solid solution with hydroxylapatite (Ca5(PO4)3OH) in biological matrices. Chlorapatite (Ca5(PO4)3Cl) is another related structure.[4]
Fluorapatite is the most common phosphate mineral. It occurs widely as an accessory mineral in igneous rocks and in calcium rich metamorphic rocks. It commonly occurs as a detrital or diagenic mineral in sedimentary rocks and is an essential component of phosphorite ore deposits. It occurs as a residual mineral in lateritic soils.[1]
Rock Type: Sedimentary
Specific Gravity: 3.1
Streak: whiteCollection
RAGM Mineral CollectionDimensions
Width
1 inDepth
1 inLength
1-3/4 inWeight
0.13 ozLocation
Location
Display Case
DS-10Room
Delmar Smith HallBuilding
Crater Rock MuseumCategory
ExhibitMoved By
Ian C.Date
January 22, 2025Notes
World case installation
