This is the polished red-brown elpidite egg. Dimensions: 1.7 x 1.3″ (4.2 x 3.4cm). Weight – 2.6oz (75 grams). Origin: Mongolia.
Some information about elpidite:
Elpidite is a rare zirconium silicate mineral that can have a very nice crystal form and provide good specimens.
Elpidite is another in the long list of unusual mineral that come from agpaitic pegmatite rocks. Agpaitic pegmatite intrusions are unusual igneous rocks that are high in alkaline metals (such as sodium) and poor in silica. These intrusions also contain a large number of unusual elements such as zirconium.
Elpidite was first discovered at Narsarsuk, Greenland, from where the first specimens were described in 1932.