Calcite from Kjørholt, Telemark, Norway
Size: 75x213x92 mm (1244 gr.)
Big poker chip calcite, white with yellow coating.
In addition you will see some smaller transparent Calcite. This is actually phantom crystals of calcite, where the first generation is covered by small crystals of pyrite.
The video is taken with extra light to highlight its structures.
Please watch video to get a better view:
I don't know when it was found, but probably 20-30 years ago.