Euclase
Mineral BeAlSiO4(OH)
About it
Pale blue to colourless prisms with one perfect cleavage, so cut stones chip easily; Ouro Preto, Brazil, and deep blue crystals from Zimbabwe and Colombia.
- Type
- Mineral
- Group
- Silicate (nesosilicate), euclase group
- Formula
- BeAlSiO4(OH)
- Hardness (Mohs)
- 7.5
- Specific gravity
- 2.99–3.1
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Monoclinic
- Colours
- colourless, pale blue, blue, green
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.