Mineralpedia Details for Pahasapaite

Named for the Lakota Sioux Native American word Pahasapa, which is the traditional name for the Black Hills after its type and only locality at the Tip Top mine in the Black Hills of South Dakota, USA. Pahasapaite occurs as “a rare late-stage mineral in seams in fractured beryl crystals, within the inner-intermediate zone of a complex granite pegmatite.” It can be found in association with englishite, roscherite, esophoite-childrenite, tiptopite, and montgomeryite.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/pahasapaite.pdf

Formula

Li₈(Ca,Li,K)_10.5Be₂₄(PO₄)₂₄·38H₂O 

Crystal System

Isometric 

Cleavage

None, None, None 

Luster

Vitreous (Glassy) 

Color

colorless, yellow green, light pink 

Streak

white 

Class

Isometric - Tetartoidal 

Fracture

Uneven 

Hardness

4.5 

WebMineral

View Pahasapaite 

Mindat

View Pahasapaite 

Special Info

Type & Only Locality

Pahasapaite is one of the rarest minerals on Earth. It is one of five minerals with beryllium, lithium, and phosphorous in its composition and has a zeolitic structure. Tiptopite, usually associated with Pahasapaite, is one of the five Be, Li, P minerals. Pahasapaite is also isometric, unlike most other phosphates found in pegmatites. It is usually faint pink to pink to slight orange.

Light pink Pahasapaite crystal, 1mm (first photo)

1mm pink crystal in micromount, type specimen. (photos 2-4). SDSM specimen.

Photos 5-8: On this specimen, there are at least two euhedral faint pink crystals to about 0.3mm and a layer of stronger pink crystalline Pahasapaite about 2mm long seen on the side underneath a layer of Englishite and Roscherite. Beryl matrix.