Cuprite from Chessy copper mines, Chessy, Auvergne-Rhône-Alpes, France

This might be the smallest specimen in my collection, but nonetheless it has a ton of character! I love how the malachite coating really helps to emphasise the geometry of the skeletal cuprite crystal. Many of these are labelled as full pseudomorphs, but in this case the original cuprite appears to be largely preserved. Second image shows the piece in 3D as a stere photo.