sedimentary and igneous

Mixed Rock Collection

Polylithic Geological Specimen Mix

Varied hardnesses (Mohs 3-7), mixed colors including reddish-brown, tan, and dark gray, dull to earthy lusters, cryptocrystalline to crystalline structures.

Identified July 28, 2026More sedimentary and igneous →

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Physical properties

Varied hardnesses (Mohs 3-7), mixed colors including reddish-brown, tan, and dark gray, dull to earthy lusters, cryptocrystalline to crystalline structures.

Formation & geological history

Formed through various geological processes including sedimentary deposition, compaction, and weathering over geological time scales in diverse environments.

Uses & applications

Used for geological education, rock tumbling, ornamental displays, and general collection.

Geological facts

This collection represents a variety of common geological formations typically found in surface deposits, riverbeds, and weathered outcrops.

Field identification & locations

Useful for beginners learning rock identification by comparing different textures, colors, and compositions side by side.

Other sedimentary and igneous specimens

See all

Pyrite

Iron Sulfide (FeS2)

mineral

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Sedimentary rock

Quartz Geode

Silicon Dioxide (SiO2) within a sedimentary or igneous host

sedimentary

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

igneous

Quartz Geode

Silicon Dioxide (SiO2) within Sedimentary or Igneous host

mineral

Pyrite

Iron Sulfide (FeS2)

mineral