Rhodonite is a manganese silicate gemstone recognized by pink body colour and dark manganese-oxide veining.

Rose aura quartz is coated quartz designed to create pink iridescent surface effects.

Rose quartz is the pink variety of quartz, usually found as translucent massive material and less commonly as transparent crystals.

Durability is part of the appeal of Royal Blue Sapphire, not merely a technical footnote. That combination of blue body colour, 9 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice. The secondary royal blue note often matters more than people expect when separating it from lookalikes.

Part of the identity of Rubellite comes from the producing regions associated with it. Collectors and lapidaries comparing similar stones often come to it for different reasons, but identification still comes back to green body colour, 7 Mohs hardness, and vitreous lustre. The secondary pink note often matters more than people expect when separating it from lookalikes.

Ruby is defined by red corundum, but not every red stone carries the same authority of colour. The most sought-after examples combine vivid saturation with enough transparency to let the red remain bright rather than murky.

Rutilated quartz is quartz containing visible rutile needles that create distinctive internal patterns.

Sapphire covers far more than blue, yet the gem remains associated with crisp colour, durability, and a polished, highly wearable finish. Its place in jewellery owes as much to resilience as to appearance.

Sardonyx is a banded chalcedony combining sard-colored and onyx-style layers.

Schorl is the black iron-rich tourmaline species widely used in mineral and decorative markets.

Selenite is a transparent crystalline gypsum variety used in decorative and collector contexts.

Seraphinite is a trade name for feather-pattern clinochlore used in decorative jewelry.

Serpentine is a group of hydrated magnesium silicates used widely as ornamental stone.

Among jewellery stones, Sky Blue Topaz stands out for combining appearance with notable wear resistance. Jewellers who need dependable wear resistance often come to it for different reasons, but identification still comes back to blue body colour, 8 Mohs hardness, and vitreous lustre. The secondary sky blue note often matters more than people expect when separating it from lookalikes.

Smithsonite is a zinc carbonate mineral used as a collector and ornamental gemstone material.

Smoky quartz is the brown variety of quartz, its colour linked to natural irradiation and trace aluminum.

Snowflake obsidian is a patterned obsidian variety containing cristobalite spherulites.

Sodalite is a blue feldspathoid mineral commonly used as an opaque ornamental gemstone.

South Sea pearl is a premium saltwater cultured pearl category known for large size and satin-like luster.

Spectrolite is a labradorite variety known for strong multicolor labradorescence.

Spessartine is a manganese-rich garnet known for bright orange brilliance.

Sphalerite is a zinc sulfide mineral prized by collectors for exceptionally high fire.

Durability is part of the appeal of Spinel, not merely a technical footnote. That combination of blue body colour, 9 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice. The secondary pink note often matters more than people expect when separating it from lookalikes.

Spirit quartz is a trade name for quartz clusters with sparkling secondary overgrowths.