Black Gilson Opal measures 11mm. Disc shape with a flat bottom, flat top and flat sides. These are cut as thin as possible, about 1mm thick.

Black Gilson Opal measures 20mm. Disc shape with a flat bottom, flat top and flat sides. These are cut as thin as possible, about 1mm thick.

This 1.5 inch diameter marble comes in multiple vibrant colors, all with a blue backing. Fantastic Dichroic Galaxy Marbles! Ready to apply to your piece. Just preheat in the kiln,...

Works with 33COE!!!

Gilson Opal Trillion 4mm Black. Sold by the piece.

Works with 33COE!!!

Gilson Opal Trillion 4mm White. Sold by the piece.

Black Gilson Opal measures 5mm with round shape and flat bottomed

White Gilson Opal measures 5mm. Round shape with a flat bottom.

Gilson Opal Rectangle 6x2mm Black. Sold by the piece.