Fluorapatito
Fluorapatito is a mineral with formula Ca₅(PO₄)₃F, in the Fosfatos group. This specimen comes from Mina Yates, Otter Lake, Outaouais, Québec, Canadá and joined the Terrium collection in 1973.
Description
A robust hexagonal prism of bottle-green translucent fluorapatite with marbled veining, and a second crystal intergrown in parallel growth. Complete pinacoid termination. Very good lustre.
History of this specimen
It belonged to Joan Astor y Vignau, a founding member of the Grup Mineralògic Català and a pioneer of photomicrography. A historic figure in Spanish mineralogy.
About Fluorapatito
Historic material hard to obtain in this quality. Apatite is a calcium phosphate that belongs to a group of minerals with different anions (fluoride, chloride or hydroxyl). The green fluorapatite from Otter Lake is one of the most recognisable local types of apatite worldwide. It is characterised by large hexagonal prismatic crystals, deep green to bottle-green colour, and high translucency often with internal strain, veils and microfractures. This "structural defect" is not a problem but its identifying feature.
About the locality
The global reference classic for large green fluorapatites. It is a deposit associated with pegmatitic environments and phosphate-rich veins, where well-formed prismatic crystals develop. It has not produced good specimens for decades, and what is obtained comes almost exclusively from historic finds.
Technical data
- Catalogue No.
- 0293
- Composition
- Ca₅(PO₄)₃F
- Name
- Fluorapatito
- Group
- Fosfatos
- Category
- Estélites
- Mine
- Mina Yates
- District / Municipality
- Otter Lake
- Province
- Outaouais
- Region
- Québec
- Country
- Canadá
- Size (cm)
- 5.3 x 3.2 x 2.4
- Weight
- 69.1 g
- Acquired
- 1973
- Ex-collection
- Joan Astor i Vignau
- Etymology
- From the Greek "apatē", "deception", due to historical confusion with other similar-looking minerals.
- Quality
- Notable
- Value trend
- Al alza