Chalcanthite
Mineral CuSO4·5H2O
Also called Blue vitriol
Take care.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
- Breaks down in damp air: Keep it dry and in steady humidity; some crumble or rot as they take on moisture.
- Toxic: Wash your hands after handling it, don't lick or taste it, and don't make dust.
About it
Bright blue copper sulfate that dissolves in water and slowly crumbles as it dries out; never taste it. Forms crusts in dry copper mines like Chuquicamata, and most large crystals for sale are lab-grown.
- Type
- Mineral
- Group
- Sulfate, chalcanthite group
- Formula
- CuSO4·5H2O
- Hardness (Mohs)
- 2.5
- Specific gravity
- 2.2–2.3
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Triclinic
- Colours
- sky blue, deep blue, greenish blue
- Transparency
- transparent, translucent
- Cleavage and fracture
- imperfect; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.