Mineral In A Matrix (Likely Quartz Or Feldspar)

Amazonite in Matrix

Potassium Feldspar (Microcline), KAlSi3O8

Schist with Biotite and Quartz

Biotite-Quartz Schist (Fe,Mg,Al silicate mix)

Que Sera Stone (Llanite with Feldspar and Quartz)

Rhyolite with blue quartz and pink orthoclase (Llanite-type quartz porphyry)

Likely weathered quartz-bearing rock (uncertain identification)

Possibly quartz-rich granite or granitic aplite; exact identification requires a clearer, larger image and tests

Coarse-grained granite or granitic gneiss

Granite: quartz + feldspar + mica; possible gneissic equivalent

Basalt with Quartz Infill

Aphanitic Mafic Igneous Rock with Silica (SiO2) inclusion

Granite (River Pebble)

Phaneritic intrusive igneous rock (Felsic)

Granite Pegmatite with Tourmaline and Muscovite

Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))

Fluorite on Matrix

Calcium Fluoride (CaF2)

Black Tourmaline in Quartz Matrix

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Tumbled quartz-rich stone, likely druzy quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Jasper

Silicon dioxide (SiO2)

Quartz-encrusted Matrix

Silicon Dioxide (SiO2) with Ferruginous Sandstone

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and biotite/hornblende

Gneiss (with Quartz Vein / Pegmatite Banding)

Metamorphic Gneiss

Rounded white pebble, likely quartz or feldspar

Most consistent with milky quartz (SiO₂), though altered feldspar or calcite is possible from the image

Banded Sedimentary Rock (Wishbone Stone / Banded Quartzite or Limestone)

Silicified limestone or banded sedimentary rock with mineral veins

Dalmatian Stone

Peralkaline rhyolite

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic rock; exact identification requires testing

Quartz-rich metamorphic rock (likely mica schist or gneiss)

Quartz–feldspar–mica assemblage; probable biotite schist/gneiss

Biotite-bearing granite or granitic gneiss

Quartz–feldspar granite with biotite and accessory mica/amphibole

Granite Pebble

Granite (Phaneritic Quartz-Feldspar Rock)

Weathered granite or granitic gneiss cobble

Granite; primarily quartz, feldspar, and mica

Small quartz-rich rock fragment (tentative)

Likely quartz (SiO₂) with possible feldspar or carbonate inclusions

Granite river rock

Granite (composed of Quartz, Feldspar, and Mica)

Quartz Crystal Cluster on Matrix

Silicon Dioxide (SiO2)

Sandstone (Quartzose / Feldspathic Sandstone)

Arenite (SiO2 principal matrix)

Iron-stained quartz-rich rock, likely granite or pegmatite fragment

Weathered granite/pegmatite; mainly quartz (SiO₂) with feldspar and iron-oxide staining

Dark volcanic rock, likely basalt

Basalt; primarily plagioclase feldspar and pyroxene, with possible olivine and alteration minerals

Weathered foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and mineral tests

Porphyry

Porphyritic Andesite or Rhyolite

Feldspar in Matrix

Feldspar group minerals in metamorphic or igneous matrix

Porphyritic Basalt or Diabase with Plagioclase Phenocrysts

Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar

Sandstone (Arkose)

Arkose Sandstone (SiO2 with KAlSi3O8)

Dragonstone (Brecciated Basalt/Diabase with Epidote and Quartz)

Brecciated mafic igneous rock

Sandstone

Sandstone (SiO2-rich framework with variable matrix)

Coarse-grained granite or granitic gneiss

Granite; primarily quartz (SiO₂), feldspar, and mica/amphibole

Milky quartz-bearing rock, possibly quartzite

Quartz (SiO₂), likely in a quartzite or quartz-rich metamorphic matrix

Polished orbicular jasper (likely ocean jasper)

Silicified volcanic rock; chiefly microcrystalline quartz (SiO₂), with feldspar and iron-rich alteration minerals

Weathered granite (likely pegmatitic granite)

Granite; predominantly quartz (SiO₂), feldspar, and mica, with possible iron-oxide alteration

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

Quartz-bearing metamorphic rock, possibly epidote/quartzite

Quartz-rich rock with possible epidote and feldspar; exact identification requires testing