Pargasite
Mineral NaCa2(Mg4Al)(Si6Al2)O22(OH)2
About it
Green to brown or black amphibole of marble, skarn, and mantle rock; named for Pargas in Finland, where it occurs in marble.
- Type
- Mineral
- Group
- Silicate (inosilicate), amphibole group
- Formula
- NaCa2(Mg4Al)(Si6Al2)O22(OH)2
- Hardness (Mohs)
- 5–6
- Specific gravity
- 3.04–3.17
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Monoclinic
- Colours
- green, blue-green, brown, black
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in two directions at about 56° and 124°
Typical values: real specimens vary. For more, see mindat.org.