Lapis Lazuli: Gemstone, Uses, Properties

Lapis Lazuli is a beautiful, deep blue gemstone with flecks of gold pyrite and white calcite. It's been prized for centuries for its color, durability, and symbolic meaning. Lapis Lazuli is a metamorphic rock composed of several minerals, with Lazurite as the key player responsible for its stunning blue color. Pyrite adds the distinctive golden "stardust" flecks, while Calcite creates the white veining. This unique combination has captivated humankind for millennia, adorning everything from pharaohs' necklaces to Renaissance artworks.

Lapis Lazuli is a rock, not a mineral. It is a metamorphic rock composed of several minerals. The most important mineral component of lapis lazuli is lazurite (25% to 40%), a feldspathoid silicate mineral with the formula (Na,Ca)₈(AlSiO₄)₆(S,SO₄,Cl)_1-2.

Lapis lazuli also contains calcite (white), sodalite (blue), and pyrite (metallic yellow). Some samples of lapis lazuli contain augite; diopside; enstatite; mica; hauynite; hornblende, nosean, and sulfur-rich löllingite geyerite.

The name "Lapis Lazuli" is believed to have originated from the Latin "lapis" meaning "stone" and the Persian "lazward" meaning "blue." This reflects the gemstone's ancient connection with the vibrant blue color it's known for.

Lapis lazuli's pigment, ultramarine, was once worth more than gold! Michelangelo used it to paint the Virgin Mary's robes in the Sistine Chapel, and it adorned countless royal portraits and religious artifacts.

Polished Lapis lazuli. Photo: New Moon Beginnings

Formation of Lapis Lazuli

Lapis lazuli forms under high-temperature, high-pressure conditions within metamorphic rocks, typically marble. The lazurite mineral within it is created when calcite-rich marble is subjected to heat and pressure, often due to tectonic activity or volcanic intrusions.

The presence of pyrite and calcite in lapis lazuli is a result of impurities in the original marble. Pyrite, a common sulfide mineral, can form as a result of the alteration of iron-bearing minerals during the metamorphic process. Calcite, a common carbonate mineral, may remain from the original marble or be introduced during the metamorphic process.

Lapis Lazuli Properties

Lazurite is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.

Color: Deep blue, often with variations like purplish blue or greenish blue. The presence and distribution of pyrite (golden flecks) and calcite (white veins) influence the overall color and pattern. The intense blue color is due to the presence of the trisulfur radical anion (S₃^-) in the crystal.

Hardness: 5-6 on the Mohs scale, making it suitable for jewelry but susceptible to scratches compared to harder gemstones like diamonds or sapphires.

Mineral composition:

As mentioned earlier, Lapis Lazuli is composed of several minerals, the main ones being:

Lazurite (25-40%) - This is the mineral that gives Lapis Lazuli its blue color.
Calcite (20-40%) - This mineral gives Lapis Lazuli its white or gray streaks and patches.
Pyrite (5-10%) - This mineral gives Lapis Lazuli its metallic flecks.
Sodalite (5-10%) - This mineral gives Lapis Lazuli its blue-green color.

Density: Lapis Lazuli has a relatively high density, ranging from 2.7 to 3.0 g/cm³. This contributes to its substantial feel in jewelry and other objects.

Transparency: Opaque, with some translucency in thin pieces.

Specific Gravity: 2.7-3.0 g/cm³, making it heavier than most gemstones.

Melting Point: Approximately 1100°C, indicating high heat resistance.

Solubility: Insoluble in water and most common acids.

Chemical Stability: Relatively stable, but can be affected by strong acids and prolonged exposure to sunlight.

Weathering resistance: Lapis Lazuli is relatively resistant to weathering, but it can be affected by strong acids and alkalis. It is also sensitive to heat and can fade in direct sunlight.

Magnetism: Lapis Lazuli is not magnetic.

Rough lapis. Photo: Arsaa Gems And Minerals

Lapis Lazuli Uses

Lapis takes an excellent polish and can be made into jewelry, carvings, boxes, mosaics, ornaments, small statues, and vases. 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 in the early 19th century when a chemically identical synthetic variety became available.

High-quality lapis lazuli has been used as a mineral pigment for over 1,000 years. Bright blue pieces of lapis are trimmed of impurities and ground to a fine powder; the powder can then be mixed with oil or another vehicle for use as a paint.

Here are some of the most prominent ways Lapis Lazuli has been used:

Ornamentation:

Jewelry: Lapis Lazuli's stunning blue color makes it a popular choice for jewelry, including necklaces, bracelets, earrings, and rings. It has been used for jewelry since ancient times, and was even found adorning the funerary mask of Tutankhamun.

Carvings and sculptures: Lapis Lazuli's hardness and beauty make it suitable for carving intricate figurines, statues, and decorative objects. Ancient Egyptians carved amulets and scarabs from this stone, while Renaissance artists used it to create sculptures and decorative pieces.

Pigment:

Ultramarine: Historically, Lapis Lazuli was ground into a fine powder to create ultramarine, a vibrant blue pigment used in paints, frescoes, and illuminated manuscripts. This pigment was highly prized for its intensity and richness, and was used by artists like Michelangelo and Vermeer. However, with the development of synthetic ultramarine in the 19th century, its use in paints diminished.

Cosmetics: In ancient times, Lapis Lazuli was powdered and used as eyeshadow and eyeliner, particularly in Egypt and Mesopotamia. Its blue color was believed to have protective and beautifying properties.

Spiritual and healing:

Metaphysical properties: Lapis Lazuli has been associated with various spiritual and healing properties for centuries. It is believed to promote truth, wisdom, inner peace, and self-expression. Some use it for meditation, chakra balancing, and energy healing.

Traditional medicine: In some traditional medicine practices, Lapis Lazuli is believed to have healing properties for the throat, respiratory system, and nervous system. However, there is no scientific evidence to support these claims.

Other uses:

Decorative objects: Lapis Lazuli can be used to create decorative objects like bowls, vases, and tiles. Its unique beauty adds a touch of elegance to any space.

Building materials: In some cultures, Lapis Lazuli has been used as a building material, particularly for columns and decorative elements. The Saint Isaac's Cathedral in Saint Petersburg features Lapis Lazuli columns.

Where is Lapis Lazuli Found

Lapis lazuli was discovered around 6,000 years ago in the West Hindu-Kush Mountains of present-day Afghanistan. Today, Afghanistan continues to be the leading producer of the gem.

While Lapis Lazuli can be found in several locations, it has a rich history and several major sources:

Afghanistan: Home to the Sar-e-Sang mine deposits, the historical source of Lapis Lazuli for ancient civilizations like Egypt and Mesopotamia. These ancient deposits in the Kokcha River valley of Badakhshan province remain a major source of top-quality Lapis Lazuli even today.

Chile: The Andes mountains house significant deposits, particularly in the Los Andes region. Chilean Lapis Lazuli is known for its intense blue color and is favored by the Inca people for their artwork and jewelry.

Russia: Mines west of Lake Baikal produce Lapis Lazuli with a slightly greener tint compared to Afghan or Chilean stones. These deposits contribute a substantial portion to the global Lapis Lazuli market.

Other: Lapis Lazuli deposits also exist in countries like Mongolia, Canada, and the United States, but their production volume is significantly lower compared to the primary sources.

Ultramarine Pigment made by grinding lapis lazuli

Ultramarine

Ultramarine is a deep blue color pigment which was originally made by grinding lapis lazuli into a powder. The name comes from the Latin ultramarinus, literally "beyond the sea", because the pigment was imported into Europe from mines in Afghanistan.

Lapis lazuli block

Metaphysical Properties of Lapis Lazuli

Lapis lazuli is often associated with wisdom, truth, and protection. It is said to promote clarity of thought and to help people to speak their truth. Lapis lazuli is also said to be a protective stone, and it is often used in meditation and other spiritual practices.