Geology and geochemistry of the Leucite Hills volcanic field

The Leucite Hills are a relatively recent volcanic field north of Rock Springs. The lavas are known as lamproites, possibly the rarest rock type on earth. Elsewhere on the earth, where olivine lamproites are found, they almost always contain diamond, thus the author set out to map this volcanic field and search for gemstones. He found the first reported occurrene of peridot (gem-olivine) in the state and proposes that the area has good potential for discovery of diamond deposits.