headbut
Paul
Found this interesting info on Spinel , apparently they are not only black , but come in all colours , even blue , which states very very rare. Well I think I have 1 that I found a couple of weeks ago, 1st thought was spinel , but put in on the torch & it shows blue from one angle & the shape if different to sapphire. Its small & will put a photo on when I can get a better shot
http://gemologyonline.com/spinel.html
http://gemologyonline.com/spinel.html