Lake Ellen Kimberlite the material, though few are of gem quality and size. While there was considerable interest in diamond exploration in Michigan’s Upper Peninsula and northern Wisconsin for several years, no diamonds of commercial interest have been found. Lake Ellen Kimberlite The Lake Ellen Kimberlite is a poorly exposed volcanic breccia located about northeast of Crystal Falls in the Upper Peninsula of Michigan. The first publication in 1981 describing the feature led to speculation that this or similar kimberlites in the area might have been the source of the diamonds discovered a century before in Wisconsin as well as a period of
Gemstone irradiation produce mixtures of blue and yellow-to-brown colors, so heating is required as an additional procedure to remove the yellowish color. In some cases, the new colors induced by artificial irradiation may fade rapidly when exposed to light or gentle heat, so some laboratories submit them to a "fade test" to determine color stability. Sometimes colorless or pink beryls become deep blue upon irradiation, which are called Maxixe-type beryl. However, the color easily fades when exposed to heat or light, so it has no practical jewelry application. Gemstone irradiation The gemstone irradiation is a process in which a gemstone is artificially