Crystals
Sea urchin
Sea Urchin Fossils • Class Echinoidea (Phylum Echinodermata) Time range: Ordovician → Recent (≈ 450+ million years) Signature: five‑fold symmetry in “regulars”; petaloid flowers & bilateral symmetry in “irregulars” Common...
Sea urchin
Sea Urchin Fossils • Class Echinoidea (Phylum Echinodermata) Time range: Ordovician → Recent (≈ 450+ million years) Signature: five‑fold symmetry in “regulars”; petaloid flowers & bilateral symmetry in “irregulars” Common...
Rutile quartz
Rutilated Quartz • Quartz with rutile (TiO₂) needles Also nicknamed: Venus’ hair • Cupid’s darts Host: Quartz (Mohs ~7, SG ~2.65) • Guest: Rutile needles (metallic gold to reddish‑brown) Signature:...
Rutile quartz
Rutilated Quartz • Quartz with rutile (TiO₂) needles Also nicknamed: Venus’ hair • Cupid’s darts Host: Quartz (Mohs ~7, SG ~2.65) • Guest: Rutile needles (metallic gold to reddish‑brown) Signature:...
Shark teeth
Shark & ray teeth (fossils) • bioapatite → fluorapatite‑rich mineralization Hardest part of a shark • skeleton is cartilage → teeth dominate the fossil record Mohs ≈ 5 (apatite) •...
Shark teeth
Shark & ray teeth (fossils) • bioapatite → fluorapatite‑rich mineralization Hardest part of a shark • skeleton is cartilage → teeth dominate the fossil record Mohs ≈ 5 (apatite) •...
Red tiger eye
Red Tiger Eye • “Bull’s Eye” / “Ox’s Eye” Species: Quartz (SiO₂) with oriented fibrous structure (chatoyancy) Origin of color: hematite‑rich oxidation • often enhanced by careful heat Hardness ~6.5–7...
Red tiger eye
Red Tiger Eye • “Bull’s Eye” / “Ox’s Eye” Species: Quartz (SiO₂) with oriented fibrous structure (chatoyancy) Origin of color: hematite‑rich oxidation • often enhanced by careful heat Hardness ~6.5–7...
Quartz with inclusions
Quartz with Inclusions • SiO₂ hosting minerals, fluids & gas bubbles Motifs: sagenitic needles • tourmaline rods • chlorite “moss” • phantoms • enhydros Mohs ~7 • SG ~2.65 •...
Quartz with inclusions
Quartz with Inclusions • SiO₂ hosting minerals, fluids & gas bubbles Motifs: sagenitic needles • tourmaline rods • chlorite “moss” • phantoms • enhydros Mohs ~7 • SG ~2.65 •...
Oolite
Oolite • Oolitic limestone (sedimentary rock) Grains: ooids (0.2–2 mm) — concentric CaCO₃ coats Mineralogy: Calcite / aragonite ± dolomite, iron oxides Environment: Warm, shallow, agitated water (shoals, tidal bars)...
Oolite
Oolite • Oolitic limestone (sedimentary rock) Grains: ooids (0.2–2 mm) — concentric CaCO₃ coats Mineralogy: Calcite / aragonite ± dolomite, iron oxides Environment: Warm, shallow, agitated water (shoals, tidal bars)...