Elutriate (v.):

1. To purify, separate, or remove (ore, for example) by washing, decanting, and settling.
2. To wash away the lighter or finer particles of (soil, for example).

[Latin (from *elutrium, vat, bath, from Greek *elutrion; see elytron) or elutriare (from elutor, one who washes, from eluere, to wash out; see elute).]

• * The American Heritage® Dictionary of the English Language, Fourth Edition. S.v. “elutriate.” Retrieved June 27 2007 from http://www.thefreedictionary.com/elutriate