sedimentary
Puddingstone (Quartzite Conglomerate with Jasper inclusions)
Metaconglomerate (Silicon Dioxide, SiO2)
Hardness: 7 (Mohs scale); Color: White, cream, or gray matrix with contrasting red jasper pebbles; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Massive; Cleavage: None (conchoidal fracture).
- Hardness
- 7 (Mohs scale)
- Luster
- Vitreous to dull
Identified More sedimentary →
Explore Puddingstone (Quartzite Conglomerate with Jasper inclusions) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: White, cream, or gray matrix with contrasting red jasper pebbles; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Massive; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the cementation of rounded pebbles (conglomerate) and subsequent low-grade metamorphism. The red inclusions are specifically Jasper. Many specimens found in the Great Lakes region date to the Huronian Supergroup of the Paleoproterozoic era, approximately 2.3 billion years ago.
Uses & applications
Used primarily as decorative lapidary material, jewelry (cabochons), paperweights, landscaping stones, and collected by rockhounds for its distinct appearance.
Geological facts
The rock gets its name because the dark red jasper pebbles resemble raisins or fruit in a boiled suet pudding. It was widely used as a 'marker stone' by early explorers in the St. Joseph Island area of Ontario.
Field identification & locations
Identify by looking for rounded red pebbles embedded in a hard, light-colored quartz or quartzite matrix. Common in glacial drift across Michigan and Ontario. It is much harder than common concrete and will scratch glass easily.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary
Brown Sandstone (River Rock)
Arenite
sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary