|Wikipedia has an article about:|
Xylopal was a form of petrified wood with a more lustrous beauty.
Xylopal was similar to tempskya (petrified wood) except the wood fiber was replaced by opal instead of quartz. Sometimes called opalized wood or lithoxyle, it was highly prized for its beauty (it made good bookends). Especially detailed pieces could be used as inlays, statuettes, or for jewelry. A typical price was 22sp per pound (49 sp/kg).
This hardstone was able to substitute for the material components of the reverse gravity, specifically the iron filings and the lodestone. It required a hand-sized amount, either in a single stone or a bag of fragments.
- Tempskya (petrified wood)