asponyx is an onyx, part or all of whose layers consist of jasper.
jasper
n.
5ME jaspre < MFr < L iaspis < Gr, a green precious stone, prob. akin to Heb yatpeh6
1 an opaque variety of colored, cryptocrystalline quartz, usually reddish, yellow, or brown
2 Bible a precious stone, probably an opaque green quartz
3 a kind of porcelain developed by Wedgwood, having a dull surface in green, blue, etc., with raised designs, usually in white