Marble
Calacatta Marble
Metamorphic · Carrara, Tuscany, Italy Rare Marble
Carrara Marble
Metamorphic · Carrara, Tuscany, Italy Common Precious
Diamond
Diamond (carbon) · Hardness 10 Uncommon Semi-Precious
Opal
Opal (hydrated silica) · Hardness 5.5–6.5 Uncommon Organic