Oil Shale Sample (Lamosite) by Gene Cooper

Lamosite is an olive-gray brown or dark gray to brownish black lacustrine-type oil shale, in which the chief organic constituent is lamalginite derived from lacustrine planktonic algae. In minor scale it also consists of vitrinite, inertinite, telalginite, and bitumen.[1]
Lamosite deposits are the most abundant and largest oil shale deposits beside of marinite deposits. The largest lacustrine-type oil shale deposits are the Green River Formation in western United States, a number deposits in eastern Queensland, Australia, and the New Brunswick Albert Formation and several other deposits in Canada.[1] (from Wikipedia)