Identify any rockfrom a photo.

Vesicular basalt (likely weathered volcanic scoria)

Basalt; chiefly plagioclase, clinopyroxene, olivine, and volcanic glass

Yellow jasper (likely iron-stained chalcedony)

Microcrystalline quartz, SiO₂, commonly colored by iron oxides/hydroxides

Weathered brown river pebble, likely sandstone or iron-rich quartzite

Indeterminate; probable quartz-rich sandstone (quartz and iron-oxide cement)

Rounded weathered stone, likely quartz-rich sandstone or fine-grained volcanic rock

Indeterminate hand specimen; probable quartz–feldspar sandstone (SiO₂-rich)

Fossil brachiopod or bivalve shell fragment

Likely a fossilized, ribbed brachiopod; exact genus/species cannot be determined from the image

Dark gneiss or amphibolite cobble

Banded metamorphic rock, likely quartz–feldspar–biotite gneiss or amphibolite

Biotite schist (possibly garnet-bearing)

Mica schist; primarily quartz (SiO₂), feldspar, and biotite mica, with possible garnet and amphibole

Likely weathered granite or granitic gneiss

Quartz–feldspar–mica rock; possibly gneissic granite

Weathered metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly in a quartz–iron-oxide host

Metallic sulfide-bearing rock, possibly galena-rich ore

Likely galena (PbS) with iron sulfides and gangue; exact identification requires testing

Graphite-rich metamorphic rock (graphitic schist)

Graphitic schist; chiefly graphite (C), quartz (SiO₂), and mica minerals

Pink-and-gray granite or granitic gneiss

Quartz–feldspar granite; possibly foliated granitic gneiss