Esperite
Mineral PbCa3Zn4(SiO4)4
Also called Calcium larsenite
Take care.
- Contains lead: Wash your hands after handling it, keep it away from children, and don't make dust.
About it
Dull white, granular lead-calcium-zinc silicate known mainly from Franklin, New Jersey; prized by fluorescent collectors for its lemon-yellow glow under shortwave UV.
- Type
- Mineral
- Group
- Silicate (nesosilicate), esperite group
- Formula
- PbCa3Zn4(SiO4)4
- Hardness (Mohs)
- 5–5.5
- Specific gravity
- 4.28–4.42
- Streak
- white
- Lustre
- greasy, dull
- Crystal system
- Monoclinic
- Colours
- white, colourless
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- poor; uneven fracture
- Under UV light
- brilliant lemon yellow under shortwave UV
Typical values: real specimens vary. For more, see mindat.org.