Ethiopian opal
Variety SiO2·nH2O
Also called Welo opal
Take care.
- Sensitive to heat: Keep it away from heat and sudden changes of temperature, including hot lights and ultrasonic cleaners.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
About it
Precious opal mined since 2008 in the Wollo area of Ethiopia. Most is hydrophane: it soaks up water and turns clear for a while, so keep it dry and away from oils.
- Type
- Variety
- Group
- Opal variety
- Formula
- SiO2·nH2O
- Hardness (Mohs)
- 5.5–6.5
- Specific gravity
- 1.75–2.1
- Streak
- white
- Lustre
- vitreous (glassy), resinous
- Crystal system
- Amorphous (no crystal structure)
- Colours
- white, yellow, orange, brown, with play-of-colour
- Transparency
- transparent, translucent
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.