Let's start with the so called "Marienglas" which the Romans already discovered in the first century AC using it as window glass and for lamps.
They gave it the name Lapis specularis (look through stone) and it became a big industry specially in Spain that time.
These two pieces I never found before as they were encased on a large pyrite crystal and came off after heavy rainfall.

It is Selenite and belongs to the mineral gypsum. It comes in many varieties and colours though...
Play of colour (cat's eye effect) at this piece

lump of crystal, mixed colours, looks like molten glass

which flower could be that? Nature at it's best..

modern art?

iron ore matrix - Marienglas

glass dripstone ?

2 kg piece

funny structure, like a sponge

colourful inclusion


could be a painting..

intermixture of everything

icicles ?


what a funny shape again

and before it get's boring, this one from hundreds I got...but if you want to see more, just tell me...

Max