sedimentary (processed mineral product)
Gypsum Wallboard (Drywall)
Hydrous calcium sulfate (CaSO4·2H2O)
Hardness: 2.0 (Mohs scale); Color: White to grey when raw; Luster: Pearly to dull; Crystal structure: Monoclinic; Cleavage: Perfect; Specific gravity: 2.3
- Hardness
- 2
- Color
- White to grey when raw
- Luster
- Pearly to dull
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2.0 (Mohs scale); Color: White to grey when raw; Luster: Pearly to dull; Crystal structure: Monoclinic; Cleavage: Perfect; Specific gravity: 2.3
Formation & geological history
Formed as an evaporite mineral in ancient sedimentary basins from the evaporation of seawater; commercially processed into panels by sandwiching core plaster between paper layers.
Uses & applications
Primary material in residential and commercial construction for interior walls and ceilings; also used as a soil conditioner and in plaster of Paris.
Geological facts
Drywall was invented in 1916 by the United States Gypsum Company but didn't become popular until the post-WWII housing boom due to its speed of installation over lath and plaster.
Field identification & locations
Identify in the field by its paper-covered surface and soft, white interior that can be scratched by a fingernail. Found in almost every modern indoor human dwelling.
More like this
Other sedimentary (processed mineral product) specimens
Slag
Ferrous slag (by-product of iron smelting)
Mineraloid / Anthropogenic
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)
Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)
mineral
Hematite Beads
Hematite (Fe2O3)
Mineral
Pyrite with Limonite/Goethite Alteration (Pseudomorph)
Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)
mineral
Wallboard/Drywall (Gypsum-based)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
sedimentary