Brazilian agate
Lapidary material SiO2
About it
Agate from the lavas of Rio Grande do Sul, Brazil, the source of most commercial agate slices, bookends, and geodes. Bright blue, pink, and green colours are dyed.
- Type
- Lapidary material
- Group
- Agate (chalcedony)
- Formula
- SiO2
- Hardness (Mohs)
- 6.5–7
- Specific gravity
- 2.57–2.64
- Streak
- white
- Lustre
- waxy, vitreous (glassy)
- Crystal system
- Trigonal
- Colours
- grey, white, brown, red; often dyed blue, green, pink, or purple
- Transparency
- translucent, opaque
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.