Re: Boulder - 'Moulder' - identification help
Your boulder appears to be granitic gneiss (metamorphosed granite)containing quartz, feldspar, mica, and a few other minerals including magnetite. It is definitely not kimberlite which is very fine grained and dark gray to bluish gray. Kimberlite weathers quickly to grayish or yellowish clay.
From Mike R - April 12, 2013 at 01:41:53