Kimberlite garnets rich in chromium, are generally absent from most other igneous rocks, making them particularly useful as indicators for kimberlites. These indicator minerals are generally sought in stream sediments in modern alluvial material. Their presence may indicate the presence of a kimberlite within the erosional watershed that produced the alluvium. The geochemistry of Kimberlites is defined by the following parameters: Kimberlites are the most important source of primary diamonds. Many kimberlite pipes also produce rich alluvial or eluvial diamond placer deposits. About 6,400 kimberlite pipes have been discovered in the world, of those about 900 have been classified as diamondiferous,
Lemei Rock around Lemei Rock include the Indian Heaven Wilderness, which is known for the high mountain meadows among its scattered volcanic peaks. The Pacific Crest National Scenic Trail passes north/south through the volcanic field and the Indian Heaven Wilderness, which is known for its lakes and views of four nearby volcanoes: Mount Adams, Mount Hood, Mount St. Helens, and Mount Rainier. Major trails at Lemei Rock are the Lemei Trail, which climbs up the east side of Lemei Rock; and Wapiki Trail, which descends from the Lemei Trail to the deep blue Wapiki Lake, the "crater lake" of Lemei Rock. The