Kristalopedia
Jadeite
Jadeite (jadeite) • monoclinic pyroxene Formula: NaAlSi2O6 Mohs ~6.5–7 • SG ~3.30–3.38 • RI ~1.66–1.68 Luster: glassy→waxy • Structure: fine-grained “sugar” mosaic This post is about jadeite only (not nephrite)...
Jadeite
Jadeite (jadeite) • monoclinic pyroxene Formula: NaAlSi2O6 Mohs ~6.5–7 • SG ~3.30–3.38 • RI ~1.66–1.68 Luster: glassy→waxy • Structure: fine-grained “sugar” mosaic This post is about jadeite only (not nephrite)...
Vesuvianite
Vesuvianite (also called idocrase) • complex calcium–aluminum sorosilicate Approximate formula: Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄ (variable) Crystal system: tetragonal • Habit: prismatic, square cross-sections, granular/massive Mohs: ~6–6.5 (up to ~7) • SG: ~3.3–3.45 •...
Vesuvianite
Vesuvianite (also called idocrase) • complex calcium–aluminum sorosilicate Approximate formula: Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄ (variable) Crystal system: tetragonal • Habit: prismatic, square cross-sections, granular/massive Mohs: ~6–6.5 (up to ~7) • SG: ~3.3–3.45 •...
Shiva lingams
Shiva lingam (Narmada lingam) • river-smoothed microcrystalline quartz (jasper/chert) with iron oxide patterns Shape: ellipsoid/egg-shaped • Finish: hand-polished from naturally smoothed river stones Mohs: ~6.5–7 • SG: ~2.6 • Luster:...
Shiva lingams
Shiva lingam (Narmada lingam) • river-smoothed microcrystalline quartz (jasper/chert) with iron oxide patterns Shape: ellipsoid/egg-shaped • Finish: hand-polished from naturally smoothed river stones Mohs: ~6.5–7 • SG: ~2.6 • Luster:...
Lava
"Lava stone" • informal term Most common: vesicular basalt / scoria (mafic volcanic rock) Igneous • Extrusive • Volcanic Textures: vesicular • scoriaceous • amygdaloidal Colors: black • anthracite •...
Lava
"Lava stone" • informal term Most common: vesicular basalt / scoria (mafic volcanic rock) Igneous • Extrusive • Volcanic Textures: vesicular • scoriaceous • amygdaloidal Colors: black • anthracite •...
Rodonites
Rhodonite • pyroxenoid group — idealized (Mn,Fe,Mg,Ca)SiO₃ (Mn dominant) Crystal system: triclinic • Morphology: massive, granular, cleavable pieces; rare prismatic crystals Mohs hardness: ~5.5–6.5 • SG: ~3.4–3.7 • Cleavage: perfect...
Rodonites
Rhodonite • pyroxenoid group — idealized (Mn,Fe,Mg,Ca)SiO₃ (Mn dominant) Crystal system: triclinic • Morphology: massive, granular, cleavable pieces; rare prismatic crystals Mohs hardness: ~5.5–6.5 • SG: ~3.4–3.7 • Cleavage: perfect...
Snowy obsidian
Snowflake obsidian • natural volcanic glass (rhyolitic) with cristobalite spherulites Structure: amorphous base glass • Texture: black glass with radial white "snowflakes" Mohs scale: ~5–5.5 • SG: ~2.35 • Luster:...
Snowy obsidian
Snowflake obsidian • natural volcanic glass (rhyolitic) with cristobalite spherulites Structure: amorphous base glass • Texture: black glass with radial white "snowflakes" Mohs scale: ~5–5.5 • SG: ~2.35 • Luster:...