Most "very Rare" minerals tend to be very tiny and very drab. This is an exception with bright blue sparkling masses of well formed crystals mixed with platy white Arsenolite crystals. This is similar to Chalcanthite but it has 7 H2O included making it "fully hydrated". This was part of the Ruth and Andy Palmer species research collection and was studied by Joe Mandarino. Almost never seen for sale and an exceptional example!