Amber colored calcite on a bed of, probably primary calcite crystals associated with minute Marcasite crystals.
Specimen from the early 1980's from the bottom of the quarry.
I remember digging out this specimen while water filled the quarry throughout small cracks in the rock. Quite impressive, you could see the water boiling up from the ground because the quarry bottom was lower than the Meuse river.
Collection and photo, Paul De Bondt.