Guide to Lapis Lazuli

History, Lore and Appreciation

Technically, lapis lazuli is a rock since several minerals combine to form it, with lazurite being its principal component, and giving the material its deep blue color. It is, in fact lapis lazuli’s intense blue color, at times flecked with white calcite and golden colored pyrite crystals that has captivated people’s attention for thousands of years. The Assyrians and Babylonians prized lapis lazuli for use as carved seals.

It was used throughout many of Egypt’s dynasties, and was referred to by them as “heaven’s stone.” Pharaoh Cleopatra VII had a particular affinity for it; aside from using it in jewelry and as an inlay for artefacts, she had it (or lazurite crystals from the same source) ground into a powder, which could then be emulsified for use as eye shadow makeup. Further, it was used as a blue pigment (called ultramarine) for many centuries. It is thought that lapis lazuli was one of twelve gems that comprised the High Priest’s Breastplate – mentioned in the Book of Exodus – an account of when the Israelites left Egypt. Lapis Lazuli, which has long been mined in Afghanistan in an area travelled by merchants along the ancient Silk Road, spread appreciation for the blue gem in the Far East as well. Interestingly, the material was long described as sapphirus, meaning that what was known as such in ancient times was lapis lazuli – and not sapphire. An example is Pliny the Elder who used the word sapphirus in describing a blue gemstone with golden spots. Actually, lapis lazuli is thought to come from the Latin lapis, stone, and Persian lajevard, blue stone, literally meaning “stone blue stone”. It was first used with this meaning in the 17th century. It is important to bear in mind that, as far as blue gems were concerned, lapis lazuli was the blue gem to covet and cherish, long before blue sapphire came to be appreciated in the West. Today, lapis lazuli is valued as a bold ornamental gem that can be beaded, fashioned into cabochons, polished for inlays and carved.

Birthstones and Anniversaries

While lapis lazuli is not mentioned as a birthstone in modern lists, it was once suggested as an alternate gem for the month of December, together with turquoise. It is considered a 9th wedding anniversary gemstone.

Description and Properties

A rock composed primarily of lazurite, calcite and pyrite. It may also contain haüynite, sodalite, and diopside.

Color(s): Medium to dark, slightly greenish blue to purplish blue, often containing metallic looking pyrite crystals and/or white to grey flecks of calcite.

Refractive Index: 1.50 or 1.67 (with lots of calcite); it can be challenging to obtain a refractive index reading for lapis lazuli.

Birefringence: None

Specific Gravity: 2.75 (±0.25) (This may vary due to mineral content).

Cause(s) of color: In lazurite, sulphur- related color centres.

Mohs Hardness: 5 to 6 (variations due to composition).

Internal identifying characteristics: randomly scattered pyrite crystals (that appear as yellow metallic flecks) and mottled white calcite crystals.

Treatments