This material was marketed as "Ocean Jasper " offered.
But mineralogically correct would be : Chalcedony with spherulites.
The source for these varieties has long been exhausted.
New material from this area is now more jasper, i.e. coarse and opaque, and the typical spherulites are barely visible or missing altogether.
This exceptionally large plate dates from the year 2000 was polished on both sides in Idar-Oberstein and is extremely difficult to obtain in this quality.
Dim: 32 x 11 x 0,6 cm
Weight: 436 g