Rock Identifier
Fired Clay Brick (Anthropic Rock substitute) (Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)) — metamorphic (man-made / anthropic)
metamorphic (man-made / anthropic)

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

Hardness: 6-7 (Mohs scale); Color: Terracotta red/orange due to Iron Oxide; Luster: Dull/Earthy; Structure: Amorphous and microcrystalline; Porous texture with tool marks.

Hardness
6-7 (Mohs scale)
Color
Terracotta red/orange due to Iron Oxide
Luster
Dull/Earthy

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Terracotta red/orange due to Iron Oxide; Luster: Dull/Earthy; Structure: Amorphous and microcrystalline; Porous texture with tool marks.

Formation & geological history

Formed through the high-temperature firing (Pyrometallurgical process) of sedimentary clay and silt at temperatures between 900°C and 1200°C. While the raw material is millions of years old, the specimen is a modern human-made artifact.

Uses & applications

Primary use is in masonry construction for buildings, walls, and pavements. Also used as a refractory material for low-temperature kilns and fireplace linings.

Geological facts

Bricks are one of the oldest known building materials, dating back to 7000 BC. The red color is caused by the oxidation of iron minerals (limonite/hematite) during the firing process; if fired in oxygen-poor environments, they turn grey or black.

Field identification & locations

Identify by the rectangular geometry, uniform texture, and presence of wire-cut or mold marks. Commonly found in urban environments, archaeological sites, and construction zones. Not a naturally occurring geological specimen.