Gemstone slabs

Do you remember the fairy tales from the East about lavish royal palaces and jewelled chests? If you look at the exotic stone slabs, you'll immediately remember. Exotic slabs look like large slices of precious stones. Different blocks of semi-precious natural stones are either solid or made up of smaller stones of the same type stacked close together and glued together with a special transparent glaze. When the polished exotic slabs are illuminated from the other side or placed in front of a window during the day, a spectacular pattern emerges. 

Exotic stone slabs are about 3-4 cm thick and, depending on the type of stone used, are more or less translucent, and some are even very translucent. Imagine polished blocks of blue agate, purple amethyst, pink quartzite, three metres high and one and a half metres wide. Slices of red jasper, greenish amazonite, brownish-orange tiger's eye, fossilised wood look dramatic. Exotic slabs even from fossils. Each slab is a painting created by nature, a one-off work of art.

Semi-precious stone slabs are about 3-4 cm thick and, depending on the type of stone, are more or less translucent, some of them highly translucent. They look like huge chunks of multicolored gemstones - blue agate, purple amethyst, red jasper, green amazonite, pink quartz, brownish-orange tiger eye, petrified wood, even fossils. Each slab looks like a genuine piece of art created by nature.

Exotic stone slabs tend to be more fragile and susceptible to environmental factors than marble or granite. Their properties depend on the type of stone used in the panels. In architecture and interiors, exotic stone slices are particularly suitable for translucent walls and decorative borders, for glamorous internally illuminated furniture, and for luxurious translucent bars and tabletops.

Different admixtures give exotic stones different shades. Often these varieties have different names, even though they may have the same composition. For example, clear colourless quartz is called rock crystal, violet quartz is called amethyst, yellow quartz is called citrine, smoky quartz is called marion, and greenish quartz is called prazem. Sometimes in stones, one colour shifts imperceptibly into another and the rest of the stone looks like another stone. Striped agates are painted in white, yellow, brown, red and black. Tiger's eyes, cat's eyes and falcon's eyes are also minerals of the quartz group. 

The properties of precious and semi-precious slabs depend on the type of stones that form them. Usually such slabs are very expensive, and not every fabricator will want to work with them. Those who will are likely to charge a lot more for fabricating products from this material than from granite or marble.

The scientist Fersman categorised precious and semi-precious stones into groups based on colour:

Colourless and white (transparent and opaque) - diamond, rock crystal, chalcedony, agate

Blue - aquamarine, topaz, sapphire, turquoise, chrysocolla, fluorite, lazurite

Purple and pink - amethyst, rhodonite

Red - ruby, spinel, hyacinth, rubellite, garnet, carnelian

Green - emerald, chrysoberyl (alexandrite), malachite, jade, amazonite

Yellow - zircon, phenakite, avantiurine

Speckled - tourmaline, jasper, feldspars

Black - obsidian, black tourmaline, smoky quartz

Colour-changing - precious opal, moonstone, sunstone, cat's eye, falcon's eye, tiger's eye

Many gems are found in Sri Lanka, known as the treasure trove of the Indian Ocean. The island is rich in garnets, zircons, tourmalines, beryls, topaz and quartz. The country's mining industry is concentrated in Ratanpura, known as the city of gems. Sun and moon stones and aquamarines come from India. Afghanistan is famous for its lazurites, Australia for its opals, Myanmar for its jadeite and Tanzania and Kenya for its tanzanite. Many semi-precious stone slabs come to Europe from the Middle East, North Africa and China.