Formula: KAl2(AlSi3)O10(OH,F)2 Monoclinic Description:Muscovite is a common mica, forming silvery to pale-colored flakes most commonly schists and granite pegmatites. It can survive weathering, and form sparkling grains in sands and sandstone. Muscovite. From the mineral collection of …
Adams County
Potassium Feldspar
Formula: KAlSi3O8 Monoclinic or Triclinic Description: Potassium feldspar refers to any of the three polymorphs microcline, orthoclase or sanidine. The distinction between these minerals can be made with certainty only after detailed X-Ray analysis. This has not …
Quartz
Formula: SiO2 Hexagonal Description: Quartz is the most abundant mineral. It is an essential component of granitic igneous rocks, of sedimentary rocks such as sandstone and chert and of metamorphic rocks such as quartzites. It is a …
Titanite
Formula: CaTiSiO5 Monoclinic Description:Titanite is a common accessory mineral usually found as tiny grains in many different rocks. It is common in plutonic igneous rocks such as granite, diorite and syenite. Titanite also is a common accessory …
Tourmaline Group
Formula: Na(Al,Fe,Li,Mg,Mn)3(Al,Cr,V,Fe)6(BO3)3Si6O18(O,OH,F)4 Hexagonal Description: Tourmaline var elbaite Animikie Red Ace pegmatite (red) showing comb texture in pegmatite wall zone. With altered Cs-beryl (yellow-green). Near Fern, Florence County, Wisconsin. (Photo by Al Falster.) Tourmaline is a complex group of …
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 …
Geologic Map of the Dells of the Wisconsin River State Natural Area
The geologic map of the Dells of the Wisconsin River State Natural Area provides a detailed look at the bedrock geology present at one of Wisconsin’s most cherished natural sites. The map and accompanying report …