Hardstone is a collective term for dense, durable ornamental stones such as agate, jasper, onyx, malachite, lapis lazuli, porphyry and rock crystal. Highly prized for their colour, hardness and ability to take a fine polish, hardstones have been used for centuries to create sculpture, jewellery, decorative objects, furniture inlays and table tops. Antique hardstone pieces are valued for both their natural beauty and exceptional craftsmanship.