Group of good-sized datolite crystals, the largest of which measures 2.8 cm. Some of the crystal faces have a brilliant glassy lustre and others have a silky finish (not matte or dull). The crystals have some very cool selective coating on certain faces, but it is not on the surface, it is underneath a “top-coat” of the silk-lustred datolite. (I have seen others with selective coating from this find where the coating gives a chalky surface with no lustre.) Internally the colour of the datolite crystals ranges from yellowy-green to a pale ice blue. No damage, incomplete crystals around the periphery where this was attached. This is a beautiful and very distinctive datolite specimen.