sedimentary
Granite Sand (Decomposed Granite)
Grus / Quartz-Feldspar Detritus
Hardness: 6-7 (individual crystals); Color: Salt-and-pepper (tan, white, pink, black); Luster: Vitreous to dull; Structure: Granular/fragmented; Cleavage: Good in feldspar grains, absent in quartz.
- Hardness
- 6-7 (individual crystals)
- Color
- Salt-and-pepper (tan, white, pink, black)
- Luster
- Vitreous to dull
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (individual crystals); Color: Salt-and-pepper (tan, white, pink, black); Luster: Vitreous to dull; Structure: Granular/fragmented; Cleavage: Good in feldspar grains, absent in quartz.
Formation & geological history
Formed through the mechanical and chemical weathering (physical disintegration) of granitic igneous rock. This process often occurs over thousands of years in varied geological environments.
Uses & applications
Used extensively in landscaping, pathway construction, driveways, and as a stable base for pavers. Also utilized in horticulture for soil drainage.
Geological facts
This material is essentially the 'DNA' of the mountain it came from; it contains the exact mineral ratio of the parent granite. When it lithifies, it can eventually become a rock known as Arkose.
Field identification & locations
Identified by the mixture of translucent quartz grains, opaque white/pink feldspar, and dark flakes of biotite mica. Look for it at the base of granite outcrops or in dry riverbeds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary