Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)

Septarian Nodule

Septarian Concretion (CaCO3 with Calcite and Aragonite)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Quartz geode

Microcrystalline quartz (SiO₂), likely a small druzy quartz geode

Amethyst-bearing quartz geode fragment

Quartz, SiO₂; purple coloration from trace iron and irradiation

Agate Geode

Silicon Dioxide (SiO2)

Blue Celestite (Celestine)

Strontium sulfate (SrSO4)

Agate Geode

Silicon Dioxide (SiO2) - variety Chalcedony/Quartz

Amethyst (Raw Cluster)

Silicon Dioxide with iron impurities (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

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.

Chert Geode or Nodule

Microcrystalline Quartz (SiO2)

Quartz geode

Quartz (SiO₂), likely a quartz-lined geode; the white crystals may include calcite

Blue Lace Agate (Geode/Druzy variant)

Chalcedony (SiO2) with Quartz druzy

Quartz Geode

Silicon Dioxide (SiO2)

Mixed mineral and rock specimen collection

Mixed assemblage, visibly including quartz, chalcedony/agate, feldspar, mica, dark mafic rocks, and possibly calcite or gypsum

Amethyst (Geode/Druzy)

Silicon Dioxide (SiO2) with iron impurities

Quartz Geode

Silicon Dioxide (SiO2)

Iron-rich concretion or weathered ironstone pebble

Goethite–hematite-bearing limonite concretion (tentative)

Basalt (Drill Core)

Mafic Volcanic Rock (Basalt)

Generic Rock Fragment

Rock Fragment

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Limonite/Goethite Iron Concretion

Hydrated iron oxide-hydroxide mixture (FeO(OH)·nH2O)

Quartz Geode

Silicon Dioxide (SiO2) in a Secondary Formation

Chert Nodule or Concretion

Microcrystalline Quartz / Sedimentary Nodule

Agate Geode with Quartz Druzy

Chalcedony (SiO2) and Quartz (SiO2)

Polished brecciated jasper

Silicified breccia, chiefly microcrystalline quartz (SiO₂) with iron-oxide staining

Geode (Chert/Quartz)

Silicon Dioxide (SiO2)

Light-colored carbonate pebble, likely limestone

Limestone; predominantly calcite (CaCO₃), possibly micritic or fossiliferous

Agate Geode

Silicon Dioxide (Chalcedony/Quartz), SiO2

Quartz-lined Geode / Chalcedony Nodule

Silicon Dioxide (SiO2)

Likely polished quartz-rich stone or calcite specimen

Uncertain; possibly quartz (SiO₂) or calcite (CaCO₃)

Quartz geode

Quartz, SiO₂; likely a chalcedony-lined geode with inward-growing quartz crystals

Tumbled quartz-rich stone, possibly milky quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Geode with Quartz Crystal Cavity

Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Quartz geode

Quartz, silicon dioxide (SiO₂), likely a chalcedony-lined geode with drusy quartz crystals

Weathered iron-rich rock, likely ferruginous sandstone or lateritic concretion

Iron-oxide–cemented sandstone; commonly dominated by quartz (SiO₂), goethite (FeO(OH)) and hematite (Fe₂O₃)

Quartz Geode

Silicon Dioxide (SiO2)

Agate / Chalcedony Geode

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Geode (Quartz)

Silicon Dioxide (SiO2)