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What is Lapis Lazuli?

Lapis Lazuli Stones

Lapis lazuli, or lapis for short, is a deep-blue metamorphic rock. It is used as a semi-precious stone. It has been prized since antiquity for its intense color. The name comes from the Persian word for the gem, lāžward. Lapis lazuli is a rock composed primarily of lazurite, pyrite, and calcite. As early as the 7th millennium BC, people mined lapis lazuli in the Sar-i Sang mines and in Shortugai. It was also mined in other mines in Badakhshan province in modern northeast Afghanistan. Lapis lazuli artifacts are dated to 7570 BC. They have been found at Bhirrana, which is the oldest site of Indus Valley civilisation. Lapis was highly valued by the Indus Valley Civilisation (3300–1900 BC). Lapis beads have been found at Neolithic burials in Mehrgarh, the Caucasus, and as far away as Mauritania. It was used in the funeral mask of Tutankhamun (1341–1323 BC).

Lapis lazuli has been used since ancient times and remains popular today. This gemstone has been prized for its bright, blue color. It is used for inlay and intarsia. It is also used for pigments for cosmetics and paintings. Its eye appeal is irresistible. Today, jewelry is its predominant use.

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Lapis lazuli value is determined almost exclusively by color. A deep, intense, blue with violet tones would be at the apex. Fine grained, uniform specimens can attain a smooth, highly polished surface not seen in lower grades.

Calcite inclusions almost always lower the value. Pyrite inclusions enhance it in the minds of many collectors and jewelry lovers. Although enthusiasts may debate how much pyrite is ideal in lapis lazuli, most would agree on one thing. The stone is better with less calcite. Calcite can appear as streaks or patches within the darker blue. It can also predominate in the mix, giving the rock an overall lighter blue shade.

Polish quality and faceting artistry also affect value.

The ancient Roman natural historian Pliny the Elder admired lapis lazuli for its colors. He called it “a fragment of the starry firmament,” because it is deep blue with twinkling bits of gold. Lapis lazuli (also simply referred to as lapis) is actually a rock. It is composed of lazurite, haüyne, sodalite, and nosean. These are all members of the sodalite group of minerals. (Lazurite itself may be considered a sulfur-rich haüyne).

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Archeologists have found lapis lazuli beads, jewelry, and carvings at numerous sites, some dating as early as 6,000 BCE. The use of this gem material for art and jewelry probably originated in Afghanistan. It spread to Asia, the Middle East, the Mediterranean, and the Roman world. In the Latin-speaking world of classical antiquity, many gemstones called sapphire or sapphirus may have been pieces of lapis. These names mean “blue stone.” In classical antiquity’s Latin-speaking world, many gemstones called sapphire or sapphirus may have been pieces of lapis. These names mean “blue stone

By the end of the Middle Ages, lapis lazuli began to be exported to Europe. It was ground into powder. The powder was made into the pigment ultramarine. Ultramarine was used by some of the most important artists of the Renaissance and Baroque. These artists include Masaccio, Perugino, Titian, and Vermeer. Ultramarine was often reserved for the clothing of the central figures of their paintings. This was especially true for the Virgin Mary. Ultramarine has also been found in dental tartar of medieval nuns and scribes. This might have been due to them licking their painting brushes while producing medieval texts. It was common when working on manuscripts.

Lapis lazuli usually occurs in crystalline marble as a result of contact metamorphism.

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Lapis takes an excellent polish and can be made into jewellery, carvings, boxes, mosaics, ornaments, small statues, and vases. Interior items and finishing buildings can be also made with lapis. During the Renaissance, lapis was ground and processed to make the pigment ultramarine for use in frescoes and oil painting. Its usage as a pigment in oil paint largely ended during the early 19th century. This change occurred when a chemically identical synthetic variety became available.

Lapis lazuli is commercially synthesized or simulated by the Gillson process. This process is used to make artificial ultramarine and hydrous zinc phosphates. Spinel or sodalite, or dyed jasper or howlite, can be substituted for lapis. (1)

Sources

(1) Wikipedia
(2) Photos by Freepik

In My Shop

Multicolor Lapis Lazuli Bracelets

$21.00

These Multicolor Lapis Lazuli Bracelets are composed of 8mm Natural Multicolor Lapis Lazuli Beads and elastic cord

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What is Sodalite?

Sodalite

Typically blue, durable, and easy to cut, sodalite is highly desired by hobbyists. Even stones that lack transparency make lovely faceted gems.

The gemstone know as sodalite belongs to the sodalite mineral group, which includes haüyne, lazurite, and nosean. All typically blue, these minerals are actually found in lapis lazuli. That is, lapis is a rock made up principally of these materials. However, sodalite and haüyne can also occur separately and even have their own varieties.

Hackmanite, a sulfur-rich variety of sodalite, shows tenebrescence. When first mined, stones from Canada and Greenland can range from pink to violet. In sunlight, however, they fade to grayish white or white. On the other hand, hackmanites from Afghanistan and Myanmar start white but turn pink or violet in sunlight. Darkness will reverse these effects.

Although both sodalite and lapis can have inclusions of calcite, you can distinguish them by sodalite’s lack of pyrite inclusions. [1}

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Laboratories have synthesized sodalites, but the natural gems aren’t rare, so no real market for them exists. However, sodalites, either natural or synthetic, can simulate other blue gems, such as lapis lazuli. Since lapis lazuli is a better known material, it’s more likely you’ll encounter sodalites offered as lapis gems, either in error or a deliberate effort to mislead.

Other popular blue gem materials, like azurite, lazulite (no relation to lazurite), and turquoise, typically show different shades of blue than sodalite. However, if the colors seem close, these stones react differently to ultraviolet testing.

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Hackmanite

Hackmanite from Dungannon Township, Ontario, Canada will luminesce bright pale pink in shortwave (SW) ultraviolet light. In longwave (LW), it luminesces bright yellow-orange. Stones may turn raspberry red after exposure to SW.

When cut, sodalite may release a hydrogen sulfide (H2S), “rotten egg,” smell due to traces of water and sulfur.

How to Care for Sodalite Jewelry

Sodalites are tough but scratch easily due to their relatively low hardness (5.5-6). Other popular jewelry stones, like quartz and topaz, will scratch them. (So will household dust, over time, with its hardness of 7-7.5). Store any sodalite jewelry separately from other pieces to avoid contact scratches. Use protective settings for ring wear. Necklace and earring use should pose fewer risks. Clean these gems only with a soft brush, mild detergent, and warm water. Consult our gemstone jewelry cleaning guide for more recommendations.

Sources

[1} International Gem Society
{2} Image by Rafe Whysall from Pixabay
[3] Nature Stock photos by Vecteezy