Crystals
Chrysocolla
Chrysocolla • Hydrated Copper Silicate (variable composition) Silica Association: Commonly intergrown with chalcedony (“gem silica” when translucent) Hardness: ~2–4 (porous) • up to ~6.5–7 when silica‑rich Typical Habits: Botryoidal crusts...
Chrysocolla
Chrysocolla • Hydrated Copper Silicate (variable composition) Silica Association: Commonly intergrown with chalcedony (“gem silica” when translucent) Hardness: ~2–4 (porous) • up to ~6.5–7 when silica‑rich Typical Habits: Botryoidal crusts...
Chiastolite
Chiastolite • variety of andalusite — Al₂SiO₅ Crystal system: Orthorhombic • Habit: prismatic crystals in slates & hornfels Signature: carbonaceous inclusions form a cross (“Maltese cross”) in cross‑section Mohs: ~6.5–7.5...
Chiastolite
Chiastolite • variety of andalusite — Al₂SiO₅ Crystal system: Orthorhombic • Habit: prismatic crystals in slates & hornfels Signature: carbonaceous inclusions form a cross (“Maltese cross”) in cross‑section Mohs: ~6.5–7.5...
Chalcopyrite
Chalcopyrite • CuFeS₂ — copper–iron sulfide Crystal system: Tetragonal • Habit: disphenoids (pseudo‑tetrahedra), massive, granular Mohs: 3.5–4 • SG: ~4.1–4.3 • Streak: greenish‑black • Luster: metallic Look: brassy yellow, often...
Chalcopyrite
Chalcopyrite • CuFeS₂ — copper–iron sulfide Crystal system: Tetragonal • Habit: disphenoids (pseudo‑tetrahedra), massive, granular Mohs: 3.5–4 • SG: ~4.1–4.3 • Streak: greenish‑black • Luster: metallic Look: brassy yellow, often...
Brachiopoda
Phylum Brachiopoda • “Lamp Shells” Marine • Filter Feeders (Lophophore) Cambrian–Recent Brachiopods 🐚 — Paleozoic Superstars with a Quiet Modern Life They look like clams, but they’re not. Meet the...
Brachiopoda
Phylum Brachiopoda • “Lamp Shells” Marine • Filter Feeders (Lophophore) Cambrian–Recent Brachiopods 🐚 — Paleozoic Superstars with a Quiet Modern Life They look like clams, but they’re not. Meet the...
Bronzite
Orthopyroxene Variety • Enstatite–Ferrosilite Series (Mg,Fe)SiO3 • Schiller “Bronze” Sheen Mohs ~5.5–6 • SG ~3.2–3.4 Bronzite 🟤✨ — Earthy Elegance with a Metallic Wink Brown at first glance, bronze at...
Bronzite
Orthopyroxene Variety • Enstatite–Ferrosilite Series (Mg,Fe)SiO3 • Schiller “Bronze” Sheen Mohs ~5.5–6 • SG ~3.2–3.4 Bronzite 🟤✨ — Earthy Elegance with a Metallic Wink Brown at first glance, bronze at...
Chrysoprase
Chrysoprase • green variety of chalcedony (microcrystalline SiO₂) Color cause: trace Ni²⁺ (nickel) in the silica +/− minute Ni‑silicate inclusions Mohs: ~6.5–7 • SG: ~2.58–2.64 • Luster: waxy‑vitreous • Transparency:...
Chrysoprase
Chrysoprase • green variety of chalcedony (microcrystalline SiO₂) Color cause: trace Ni²⁺ (nickel) in the silica +/− minute Ni‑silicate inclusions Mohs: ~6.5–7 • SG: ~2.58–2.64 • Luster: waxy‑vitreous • Transparency:...