How to judge Lapis Lazuli

LAPIS Lazuli is one of the most popular of ornamental gemstones. The popularity of this gem may have derived from its ritual significance. In ancient times it was known under the term sapphire.

The present name is said to have originated from the Latin lapis (stone) and the Arabic word azul or allazward, which describes all shades of blue. The colour of lapis lazuli was popular amongst the grand old masters of art. Today, the blue pigment is still applied to restore and renovate historical colours.

Lapis lazuli which is free of white calcite veining and pyrite (golden flecks), and displaying a pure and rich blue colour, is the rarest and most desirable in terms of quality.

The more commonly available lapis lazuli contains calcite, which produces a mottled blue and white appearance. In such stones, yellow metallic specks of pyrite are nearly always present as well, thereby disrupting the overall texture and value of the stone.

Lapis lazuli is a rock consisting of several different minerals. As with all rocks, composition varies. Due to its harmonious colour, most lapis is sold as signet stones,necklaces, carvings, beads or cabochons, revealing an interplay of music and poetry. Today, lapis is one of the most popular stones for men’s jewellery. Afghanistan isthe well known source for lapis lazuli of the finest quality. Other sources like Burma, Chile, Pakistan and Russia produce less uniformly blue and lighter, less valuable varieties. Prices vary depending on colour, craftsmanship and quality.

Treatments and imitation: A lapis lazuli-like material has been manufactured by Pierre Gilson and others, but most experts do not consider this a true synthetic. Lapis lazuli may be dyed to improve colour but the stability of the colour depends on the type of dye. Coatings have been frequently applied to hide surface defects and to improve colour. Some lapis lazuli may be crushed and bonded with plastic to improve colour and texture. The most frequently encountered imitations are glass and sodalite.All treatments should be disclosed at all levels of the distribution chain. If you are doubtful, consult a reputed gem testing laboratory.