Pyrolusite

Origin: Alberta Township, Baraga Co., Michigan, USA

Sample size: top 4 x 4 x 2 cm, bottom 3 x 2 x 2 cm

Origin: Clara mine, Wolfach, Schwarzwald, Baden-Württemberg, Germany

Sample size: 3.5 x 3.5 x 2 cm

Origin: Taylor mine, Alberta Township, Baraga Co., Michigan, United States

Sample size: 3 x 2 x 2 cm

Brassy coloured, platy crystals to 8 mm in open vug

Origin: Alberta, Canada

Ex. Erling collection

Sample size: 5 x 2.5 x 2.5 cm

Photo courtesy of:

Tom Loomis

Dakota Matrix Minerals

Origin: Michigan, U.S.A.

Owner: Milton Speckels

Sample size: about 7 cm high

Photo courtesy of:

Milton Speckels

Photo-Atlas of Minerals

Manganese nodule, these specimens are comprised primarily of manganese oxide - most likely pyrolusite

Origin: "Davey Jones Locker", Pacific Ocean, Off the coast of Alaska, U.S.A.

Sample size: about 3 cm across

This specimen consists of feathery interlocked crystals of pyrolusite. There is also a surface coating of wad. Wad is a term used to describe amorphous mixtures of manganese oxides.

Pyrolusite with calcite

Origin: Ilfeld, nr. Nordhausen, Thuringa, Germany

Sample size: 4.2 x 3.5 x 3 cm (top), 6.2 x 4.5 x 2.8 cm (2nd row)

This is a specimen of both manganite and pyrolusite. The term varvicit is used to describe this as a mixture of the two minerals. Essentially there are crystals of manganite with soft pyrolusite filling the gaps between crystals.

Origin: Öhrenstock, Ilmenau, Thuringa, Germany

Sample size: 6.2 x 4.5 x 2.8 cm