In the ancient world, lapis lazuli was worn to signify rank and wealth, having been used by kings and nobles as seals to mark their official documents.
It has long been associated with wisdom, protection, love and healing.
During the Renaissance the gem was prized by European artists. Ground to a fine powder, lapis was the source of a colour pigment called ultramarine.
It was an expensive material used only by artists of established reputation for religious works and private commissions by wealthy sponsors.
Lapis lazuli is an aggregate comprised primarily of lazurite, calcite and pyrite. Quality lapis consists mainly of lazurite – which gives the gem its intense blue colour – with small amounts of white calcite and pyrite.
It is the metallic flash of pyrite against the deep blue of lazurite that makes it so attractive to gem collectors and jewellery artists. Lesser quality lapis will often
be a faded blue, without the depth and brightness of the finer quality, and will have a greater concentration of calcite.
Under a microscope, lapis lazuli looks like the night sky – with depths of blue lazurite, a fine white haze of calcite and the starlike sparkle of pyrite.
Lapis ranges in colour from greenish blue to rich royal blue and violet blue. The most prized – and valuable – is an intense royal blue featuring minute gold flashes of pyrite.
Afghanistan is considered the most significant source of quality lapis. The gem has been mined there for thousands of years in a remote and inhospitable region, known historically as Bactria.
From isolated valleys, lapis was transported by camel caravan to the bazaars of the Mediterranean and then westwards to the gem trading houses of Europe.
Today, other sources are Lake Baikal in Siberia, Chile, Angola, Pakistan, Canada and Colorado in the US.
Lapis has long been fashioned into beads, cabochons, inlays and free-form shapes. Historically, the gem was also valued as a carving material for ornaments, hair combs, game board pieces and protective amulets.
Lapis is often treated. It is a porous gem that lends itself to waxing and oiling to improve its lustre. Lesser quality lapis is often dyed to reduce the appearance of calcite and to enhance the blue of lazurite.
As high-quality lapis is expensive there are imitants on the market; jasper stained blue and called ‘Prussian blue’ or ‘Berlin blue’ is one to note.
To detect staining, look for dye between the grains of the gem and the tell-tale gleam of transparent quartz, which is not present in natural lapis.
Sintered synthetic spinel – to which pyrite is added during the sintering process
–is another imitant. Sintering involves compacting synthetic materials to make a solid mass.
Sodalite is a gem that, to the untrained eye, can look like lapis. It is not the rich royal blue of lapis, but rather a greyish blue. Look for the absence of pyrite and evidence of dyeing – such as uneven colour and patches of dye in and around bead drill holes.
Reconstructed lapis lazuli is made from low quality lapis crushed and bonded with resin. Pyrite is added to the mix. To identify it, look for a smooth surface texture even on chipped surfaces, a colour that looks ‘too perfect’, and the absence of calcite.
As lapis is considered a relatively soft gem, use mild soapy water to clean. Rinse and leave to dry. Avoid using harsh chemicals or an ultrasonic cleaner.
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