wrote:
Has anyone that has worked in a mill ever seen anything like this?

http://www.flickr.com/photos/12599760@N00

Have any idea how it would be formed? It mainly consists of aluminum,
with small amounts of silicon, silver, and a few other things. It's
makeup seems to be similar to a casting aluminum.

Thanks for any help.

Looks much like a stalactite that I found on the underside of a metal
cutoff (Radiac?) saw table. Sparky hot bits of steel accumulated and
fused together there.