Ornamental gemstones are non-transparent minerals and rocks, with a variety of colours, textures and patterns. On the Mohs scale, the majority of these stones have a hardness of seven or less.
The following list takes a look at what makes ornamental gems valuable and attractive:
- Chalcedony – Has fine grains and a waxy sheen. Chalcedony varieties include green Chrysoprase, brownish-red to orange Carnelian, black-and-white Onyx, and brown-and-white Sardonyx.
- Jasper – Has a rough, grainy form. Its colour comes from iron inclusions.
- Aventurine – Translucent and produces aventurescence (optical reflectance), with green, brown and blue colours.
- Bloodstone – Also called heliotrope. It’s bright to dark green with red spots.
- Agate – Has concentric layers, with various colours and patterns. Fire agate has iridescent layers. Dendritic agate is whitish-grey, with fern-like patterns.
- Dumortierite – A unique, deep blue colour.
- Geodes – Rock formations with crystal cavities.
- Tiger's eye – Gold, brown or green, with chatoyant stripes.
- Pietersite – Has swirling blue, red, gold and brown colours.
- Lapis lazuli – Deep blue colour, with pyrite spots and streaks. Used since ancient times.
- Sodalite – Blue with violet tints and white calcite veins.
- Malachite – A popular and polished stone, with green circular bands.
- Chrysocolla – Found in a combination of colours, particularly blue and green.
- Turquoise – Pale blue colour. Popular and valued since ancient times.
- Howlite – Greyish-white vein patterns, also known as white turquoise.
- Rhodochrosite and rhodonite – Pale-pink to rose-red colours. Rhodochrosite has alternating zigzag stripes and circular patterns. Rhodonite has black-and-brown patch and vein patterns.
- Moonstone – Produces adularescence, a shimmering light effect.
- Amazonite – A green variety of microcline. It takes its name from the Amazon River, Brazil.
- Labradorite – Produces a schiller effect, with metallic shimmers.
- Sunstone – Displays a spangled appearance.
Comments (0)