KENOSHA COUNTY: A subsurface diamond-bearing lamprophyre diatreme has been discovered in Kenosha. The body has an area of about 50 acres. Drill core samples have small but “sharp-edged octahedra or macles, some showing intricate growth patterns and trigons”. Associated minerals include pyrope (both low Cr and high Cr), Cr-diopside, picroilmentite, Cr-spinel, serpentine, calcite and micas. Traces of millerite, clestine, barite and apatite are also reported. (Carlson and Adams, 1997).
OZAUKEE COUNTY: A white 6.57 carat diamond was found in 1881 near the Milwaukee River, about 4 km. north of Saukville. The diamond is described as rounded, almost spherical with dodecahedral faces (Olson, 1958; Vierthaler, 1958; Cannon and Mudrey, 1981).
MANITOWOC COUNTY: Several uncut diamonds were found in 1913 in the cabin of a desceased hermit near the town of Collins. Cannon and Mufrey (1981) suggest that the diamonds were found in local gravels.
PIERCE COUNTY: At least 10 small yellowish diamonds were found from1890 to 1892 during gold placering operations in near the junction of Plum Creek and Rock Elm Creek near Rock Elm. A second find in 1906 has been alleged to be bogus (Cannon and Mudrey, 1981; Cordua, 1987).
RACINE COUNTY: In 1903, an irregular rounded 2.11 carat diamond was found in Burlington (Hobbs, 1901; Cannon and Mudrey, 1981). Previously a 2.06 carat white twin was reported found there in 1897 (Eckert, 1980).
I know I’m grasping at straws here...but apparently there are diamonds in Wisconsin:
https://wgnhs.wisc.edu/minerals/diamond/
KENOSHA COUNTY: A subsurface diamond-bearing lamprophyre diatreme has been discovered in Kenosha. The body has an area of about 50 acres. Drill core samples have small but “sharp-edged octahedra or macles, some showing intricate growth patterns and trigons”. Associated minerals include pyrope (both low Cr and high Cr), Cr-diopside, picroilmentite, Cr-spinel, serpentine, calcite and micas. Traces of millerite, clestine, barite and apatite are also reported. (Carlson and Adams, 1997).
OZAUKEE COUNTY: A white 6.57 carat diamond was found in 1881 near the Milwaukee River, about 4 km. north of Saukville. The diamond is described as rounded, almost spherical with dodecahedral faces (Olson, 1958; Vierthaler, 1958; Cannon and Mudrey, 1981).
MANITOWOC COUNTY: Several uncut diamonds were found in 1913 in the cabin of a desceased hermit near the town of Collins. Cannon and Mufrey (1981) suggest that the diamonds were found in local gravels.
PIERCE COUNTY: At least 10 small yellowish diamonds were found from1890 to 1892 during gold placering operations in near the junction of Plum Creek and Rock Elm Creek near Rock Elm. A second find in 1906 has been alleged to be bogus (Cannon and Mudrey, 1981; Cordua, 1987).
RACINE COUNTY: In 1903, an irregular rounded 2.11 carat diamond was found in Burlington (Hobbs, 1901; Cannon and Mudrey, 1981). Previously a 2.06 carat white twin was reported found there in 1897 (Eckert, 1980).
Wonder what the double meaning is.