Calcite on Siderite from Dalnegorsk

Size: 4.1 x 4.4 x 3.7cm

Weight: 54g

This is a really unusual and unique specimen from Dalnegorsk. We've never seen anything quite like it. This is an egg-shaped Siderite cast with calcite on it and also inside of it. You can see that the main structure is made of many interconnected siderite crystals which likely grew around some other mineral before dissoving away leaving this hollow Alien-egg form. Inside of it is another world if calcite crystals similar to the ones on the outside. 

This specimen comes with a custom display base.