ALMANDINE Fe3A12(SiO4)3 ISOMETRIC

Almandine

Almandine (red) with amphibole and talc, Black River Falls, Jackson County, WI. Largest crystal is 1 cm. across.

Almandine is a common garnet found in a many metamorphic rocks such as schist, gneiss, amphibolite and iron formation. It is commonly associated with micaceous minerals such as muscovite, biotite and chlorite and with less common metamorphic minerals such as kyanite, staurolite, sillimanite, and cummingtonite. Almandine is the iron-aluminum end member of the garnet group; most almandine has some manganese and/or magnesium content and grades into the spessartine and/or pyrope end member.

ASHLAND COUNTY: Minute garnet crystals, likely almandine, are found in fine-grained actinolite-magnetite-chlorite-quartz slates along the Bad River Gorge at Penokee Gap west of Mellen (NW 1/4 and NE 1/4 Sec. 14 T.44N. R.3W.) (Van Hise and Irving, 1892).
- Tiny pink almandine porphyroblasts are found in the Ironwood Iron formation associated with magnetite, grunerite and other minerals. Some localities are at Mt. Whittlesey (SE sec. 9 T.44N. R.2W.) and at the Hanna Mining Co. test pit in SW SE sec 18 T.44N. R.3W. (Laybourn, 1979).

CHIPPEWA COUNTY: Small almandine garnets are found in amphibolite and gneiss in outcrop along the Chippewa River north of Cornell in the NE sec. 18 T.31N. R.6W. (Myers, et. al., 1974)

EAU CLAIRE COUNTY: Coarse anhedral masses of almandine up to 12 cm. in diameter occur in gneisses with hornblende, plagioclase and cummingtonite at Big Falls Park on the Eau Claire river (NW SE sec. 13 T.27N. R.8W.). (Myers, et. al., 1974; Cummings, 1984).

FLORENCE COUNTY: Euhedral crystals of reddish-brown almandine up to 5 cm. in diameter are found in a layer of biotite schist in the Quinnesec Formation outcropping on Hwy. 101 in Sec. 28 T.39N. R.17E. (Dutton, 1971).
- Almandine is a common constituent of the Michigamme Slate throughout the county where it is associated with biotite, muscovite and hornblende. Garnetiferous horizons can be found in sec. 9 and 32 T.40N. R.18E., in sec. 6 T.39N. R.18E. and elsewhere.(Dutton, 1971).
- Also found in the Michigamme slate as "equant clusters and granular aggregates" with chlorite, stilpnomelane and quartz near Commonwealth in Sections 31 and 32 T.40N. R.18E. (Dutton, 1971).
- Almandine is a component of the iron formation interleaved with the Michigamme slate, where it is found with magnetite and grunerite in the Dunkel test shaft and adit. (Dutton, 1971).
- Zoned elongated almandine crystals are in slate at the spillway of the Pine River Dam, west of the center of sec. 28 T.39N. R.18E., south of Florence. (Inst. Lake Sup. Geo., 1973).
-A garnet of unspecified composition, likely almandine is a common component of the Hoskins Lake Granite in the county. (Sims, et. al., 1992).

IRON COUNTY: Almandine occurs in schists and gneisses with kyanite, staurolite, quartz and biotite in sec. 28, 29, 32 and 33 T.42N. R.4E. near Powell. Good outcrops occur in SE SW sec. 28 and SW SW sec. 29 T.42N. R.4E. (W.G.N.H.S. files).
Almandine occurs in biotite gneiss in SW NE sec. 4 T.41N. R.2E. in the southern part of the county. (Sims, et. al., 1985).

JACKSON COUNTY: Almandine is common in the rocks at the Jackson County Iron Mine, east of Black River Falls at the SE 1/4 Sec. 15 T.21N. R.3W. The iron formation may contain almandine porphyroblasts up to 2 cm in diameter and bands or lenses of solid almandine up to 15 cm. thick. These garnets are associated with magnetite, quartz and actinolite; and may be partly rimmed and replaced by a complex mixture of biotite, chlorite and amphiboles. Almandine is also present in schists associated with the iron formation where it is found with muscovite, biotite, chlorite, staurolite, andalusite. Finally, porphyroblasts up to 5 cm. across can be found in talc schist associated with anthophyllite, andalusite and kyanite. In the talc schist, the almandine may be partly to completely replaced by a mixture of biotite, chlorite and cummingtonite. (Jones, 1978).

MARATHON COUNTY: Small brown crystals of almandine, containing significant manganese, occur in mariolitic cavities in pegmatites of the Wausau pluton, such as are exposed in the rotten granite quarries in sec. 19 and 20 T.28N. R.7E. (Falster, 1987; Falster et. al., 2000).
- Small almandine grains are locally abundant in gneiss in Eau Claire Dells County Park, SW sec. 7 T.29N. R.10E. (Inst. Lake Sup. Geol., 1973).
- Small yellow-brown garnets, possibly a result of contact metamorphism by the Wolf River Batholith, are found in outcrop along Artus Creek (NW NE sec. 29 T.29N. R.6E. (LaBerge and Myers, 1983).

MARINETTE COUNTY: A garnet of unspecified composition, likely almandine is a common component of the Hoskins Lake Granite through the county. It also occurs in aplite in SW SW sec. 21 T.37N. R.18E. (Sims et. al., 1992).
- small garnets, likely almandine, occur with chlorite, tourmaline and sulfides in the outcrop at Pine Rapids (AKA "LaSalle Falls") NW SE sec. 30 T.39N. R.18E. (Schulz and LaBerge, 2003).
- small ganrets are locally abundant in the schists along the Pine River Flowage in NE SW sec. 28 T.39N. R.18E. (Schultz and LaBerge, 2003). <

PRICE COUNTY: Almandine is a common component of schists with hornblende and biotite found west of Fifield at NW SW sec. 20 T.39N. R.2E. (Hotchkiss, 1915).
- Occurs in biotite schist exposed near Park Falls, as in NW SE sec. 11 and SW SW sec. 11 T.40N. R.1E. (Sims, et. al., 1985).
- Almandine is common in crenulated felsic gneisses in SW SW sec. 11, SE NW sec. 15 and NW sec. 16 T.40N. R.1E. along the east shore of Blockhouse Lake, near Park Falls, (Hotchkiss, 1915; Ringquist, 1952).
- Almandine occurs in the metavolcanic tuffs at the Ritchie Creek massive sulfide deposit. (DeMatties, 1990).

WOOD COUNTY: Almandine crystals up to 1" in diameter are reported associated with talc, serpentine, actinolite, brucite and magnetite in the soapstone quarries near Milladore (Crowns, 1976).

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