Mascagnite

Object/Artifact

-

Crater Rock Museum

Name/Title

Mascagnite

Entry/Object ID

2009.62.45

Description

Chemical Composition: Sulfate Crystal System: Triclinic System Description: Common Name: Mascagnite Chemistry: (NH4)2 SO4 Ammonium Sulfate Group: Sulfate Location: Geyser Creek, Sonoma County, California Description: White with a botrydail crystal structure PHYSICAL PROPERTIES: Lustre: Vitreous, Dull Diaphaneity (Transparency): Transparent, Translucent, Opaque Colour: Colourless, grey, yellowish-grey, yellow; colourless in transmitted light Hardness (Mohs): 2 - 2½ Tenacity: Sectile Cleavage: Distinct/Good On {001}. Parting: Twin gliding with K1(110), K2(130). Fracture: Irregular/Uneven Density (measured): 1.768 g/cm3 Density (calculated): 1.769 g/cm3 Crystallography of Mascagnite Crystal System: Orthorhombic Occurrences of Mascagnite: Geological Setting: Sublimation product from fumeroles, solfataras, burning coal seams. Fracture: Uneven Hardness: 2 Gypsum Luster: Vitreous Occurrence: Occurs at active volcanic fumaroles, hot springs, and on burning coal mine dumps Rock Type: Sedimentary Specific Gravity: 1.7 Streak: white Texture: crystaline Variety: Mascagnite is a rare ammonium sulfate mineral (NH4)2SO4. It crystalizes in the orthorhombic system typically forming as stalactitic masses exhibiting good cleavage. It is soft (not higher than 2.5 on the Mohs Scale) and water soluble. Optical properties are variable; the purest form is transparent and colorless, but opaque gray or yellow deposits are also known. It occurs in fumaroles, as at Mount Vesuvius and associated with coal seam fires. It was named for Italian anatomist Paolo Mascagni (1752-1815) who first described the mineral.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

9 in

Depth

3 in

Length

8-1/2 in

Weight

3 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Shelf

CS-F-2

Room

Curation Storage

Building

Crater Rock Museum

Category

Permanent

Moved By

Jillian Mather Kettley

Date

February 21, 2024