Formula: Mg3Al2(SiO4)3 Isometric Description: Pyrope is a magnesium-rich member of the garnet group found in rocks such as lamproites, anorthosite, serpentinite and their metamorphosed equivalents. It may survive weathering as a heavy detrital mineral. The chromium-rich member …
Kenosha County
Serpentine
Formula: Mg3Si2O5(OH)4 Monoclinic, orthorhombic, hexagonal Description: Serpentine is a family of polymorphs that include the flaky to platy antigorite, massive lizardite and fibrous clinochrysotile, orthochrysotile and parachrysotile. The polymorphs are often intimately intergrown in a particular rocks, …
Spinel
Formula: MgAl2O4 Isometric Description:Spinel is found as an accessory mineral in mafic to ultramafic igneous rocks, in marbles and other metamorphic rocks and as a rare heavy mineral in placer deposits. It is usually in small, dark …
Zircon
Formula: ZrSiO4 Tetragonal Description: Zircon in tabular crystal from the Nine Mile Pluton near Wausau in Marathon County, Wisconsin. Scanning electron microscope image. (Photo by Al Falster.) Zircon is a common accessory mineral found in many different …