No, your eyes do not deceive you.  This is a CRYSTAL of kornerupine.  Discovered in Greenland in the late 1800's, kornerupine is a rare gemstone that is today usually recovered from Burmese alluvial deposits.

Needless to say, those rounded examples rarely display visible crystals, and are best suited to faceting.  Under strong lighting, as in the photogrpahs, this terminated prism shows hints of its green undertones near the edges, though it is heavily included and not suitable for cutting.

This is a large crystal of a very rare gem species--I would argue that today it is among the most difficult gem species to obtain in specimen form, along with grandidierite, poudretteite, and taaffeite.

These things just do not come up for sale.