There are three major assemblages ofminerals found on the Keweenaw peninsula. The first are the minerals that makeup the volcanic rocks. The second are the minerals that are foundin the fissures and amygdaloids of the volcanics and conglomerates. A thirdgroup are the minerals that formed from the weathering of the primary oreminerals.

Mineralogy of the district (after Heinrich, 1976)

   Basalt rock forming minerals - albite, andesine,apatite, augite, bytownite, chamosite, hematite, hornblende, hypersthene,iddingsite, ilmenite, labradorite, magnetite, oligoclase, olivine, pigeonite,sphene.

   Rhyolite rock forming minerals - apatite,hematite, orthoclase, quartz, sanidine, tourmaline.

   Ore vein minerals - albite, algodonite, analcite,anhydrite, ankerite, apophyllite, arsenical copper, babingtonite, barite, bornite, brucite, chabazite,chalcocite, chalcopyrite, chloanthite, copper, covellite, datolite, delessite,diabanite, digenite, α-domeykite, β-domeykite, epidote, faujasite,fluorite, gypsum, hematite, heulandite, laumontite, leonhardite, maucherite,mesolite, microcline (adularia), monazite, muscovite (sericite), natrolite,niccolite, pararammelsbergite, pennine, phillipsite, powellite, prehnite, prochlroite,pumpellyite ( including var. chlorastrolite), pyrite, quartz, rammelsbergite,saponite, silver, smaltite, sphalerite, stilbite, thomsonite, thuringite,wairakiite, xonotlite.

   Supergene minerals - annabergite, anthonyite,atacamite, azurite, buttenbachite, calumetite, cerargyrite, chrysocolla,covellite, cuprite, dioptase, erthyrite, freirinite, gephardtite, guerinite, gypsum, halite,kaolinite, kinoite, malachite, mirabilite, nantokite, olivenite, paramelaconite,paratacamite, picropharmacolite, plancheite, rauenthalite, tenorite, trichalcite,tyrolite, vladimirite.

Cliff mine mineralogy –  adularia, albite,analcime, azurite, babingtonite, barite, calcite, chalcocite, chamosite,chrysocolla, copper, covellite, cuprite, datolite, epidote, fluorapophyllite,galena, gypsum, hematite, laumontite, microcline, natrolite, prehnite,pumpellyite, pyrite, quartz, silver, sphalerite, tenorite, thomsonite.

Mineralogy of the conglomerate lodes –  barite, calcite,chalcocite, chrysocolla, copper, cuprite, epidote, laumontite, malachite,microcline, orthoclase, powellite, pumpellyite, quartz, silver, and tenorite.

Mineralogy of the White Pine Mine

   Original minerals in Nonesuch shale - chlorite,epidote, illite, orthoclase, plagioclase, quartz.

   Diagenetic minerals in Nonesuch shale - calcite,chlorite, laumontonite, pyrite, quartz.

   Stratiform copper deposit minerals - bornite,chalcocite, chalcopyrite, copper, covellite, digenite, djurleite, galena,greenockite, hematite, pyrite, silver, sphalerite.

   Vein minerals - barite, bastnaesite, bismuth,bornite, calcite, calumenite, chalcocite, chalconatronite, chalcopyrite,chlorite, copper, covellite, cuprite, dolomite, domeykite, galena, greenockite,graphite, illite, malachite, microcline, montmorillonite, molybdenite, pyrite,quartz, silver, sphalerite, synchysite.

Calcite from the district often had inclusions of copperwhich gives the calcite a distinctive pinkish hue ( specimen is 7.5 cm high).	Analcime,Phoenix Mine, (largest crystal is 2.5 cm. across).

Calcite twin with inclusions of copper (probably from the Quincy mine) Seaman museum specimen 7.5 cm. across.

Seaman Museum Calcite page1 

Quartz crystals ( specimen is 7 cm across) from the district are relatively rare,although most ore contained some associated quartz. Quincy Mine Pewabic lode.	Thomsonite - Michigan 5cmacross.

Group of chalcocite crystals from the White Pine mine( 4.5 cmacross). Thesewere some of the first mineral specimens to come from the mine.	Group of copper crystals with a crystals of barite ( largestbarite is 2.5cm long) from White Pine Mine.

Adularia on copper wire. Osceola mine. Seaman Museum Specimen #957. 3 cm. high.	Analcite. Franklin Jr. Mine. Seaman Museum specimen. 5 cm. high.

 

Datolite (crystal) on prehnite, Osceola mine. Crystalline datolite is relatively rare in the district. Seaman Museum specimen.	Prehnite, Tamarck Jr. mine. Seaman museum specimen.

Natrolite from the St. Clair mine. Seaman museum specimen

Seaman Museum other minerals page.

Other photographs of minerals fromthe district.

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