Description: As far as opal goes, this is mostly the iron stone host rock, hence C Grade. There are definitely opal areas, but they are all small, and no runs. The host rock is very stable, and the material workable... but not a lot of flash will come of it.
Chemical Composition: SiO2
Grade: Semi Precious
Appearance: Translucent/ Opaque
Inclusions: A lot of matrix.
Cost per Gram: $0.35
Approximate size of 1 pc: 7.5cm x 5.5cm x 1.5cm
Approximate weight of 1 pc: 120g
Rough is rough. We do our best to grade and describe pieces in the lot, but ultimately, they all differ.