Lapis lazuli is a deep blue semi-precious stone that has been prized since antiquity for its intense color. Lapis lazuli is often referred to simply as “lapis”. This prized blue stone has been used for jewelry, carvings, and pigments since the earliest civilizations arose. Many blue stones can resemble lapis lazuli, so it is important to learn how to identify genuine lapis. By understanding the properties and characteristics of lapis lazuli, you can determine if a blue stone is true lapis or an imitation.
Properties of Lapis Lazuli
Lapis lazuli is composed of the minerals lazurite, calcite, and pyrite. Lazurite is responsible for the vibrant blue color, while calcite lends a white marbling and pyrite appears as gold flecks. The best quality lapis has a rich, uniform blue color with little veining or pyrite. Lower grades may have more white calcite or pyrite. Genuine lapis lazuli rates 5-6 on the Mohs hardness scale, so it can be scratched by common steel. The blue color comes from trace amounts of sulfur in the lazurite and is heat sensitive. Heating lapis lazuli will cause it to fade or turn greenish or gray.
Color
The most important characteristic of lapis lazuli is its vivid ultramarine blue color. This saturated medium to dark blue is highly prized. Lapis ranges from a light to a dark blue, appearing almost purple under some light. Lower quality lapis has pale grayish or greenish tints. The blue color should be consistent throughout a stone with no streaks or concentrated patches of color. Imitation stones like sodalite often appear too purple or gray to mimic real lapis.
Flecks
Genuine lapis lazuli usually contains flecks of golden pyrite. These brassy metallic flecks add interest and value to the stone. The flecks should be small, uniformly distributed specks. Large concentrated patches or an overabundance of pyrite indicates a lower quality stone. While pyrite flecks are typical, their absence does not necessarily mean a stone is not real lapis. However, imitation stones like sodalite lack pyrite flecks.
Veining
Most lapis lazuli contains white calcite veins running through the blue stone. Thin jagged veins that follow a consistent direction are typical. The veining gives lapis a marbled look. But too much veining diminishes the value and indicates a poorer quality stone. Imitation blue stones like sodalite lack the white calcite veins. However, the absence of veining alone does not confirm a stone is genuine lapis.
Hardness
Lapis lazuli has a hardness of 5-6 on the Mohs hardness scale. This means it can be scratched by common steel knives or tools, which have a hardness near 5.5. Genuine lapis lazuli will show signs of abrasion when scraped against steel. Harder stones like sodalite, azurite, and lapis simulants will not scratch as readily. Testing the hardness can help determine if a blue stone is real lapis lazuli.
Marbling
The marbling of lapis lazuli is caused by veins of white calcite running through the blue lazurite. This gives lapis a distinctive, fine-grained, marble-like pattern. The blue and white should form thin uniform lines, not concentrated patches. Marbling is typical of natural lapis lazuli, while simulants like sodalite lack this patterning.
Fracture
Lapis lazuli has a splintery, conchoidal fracture. This means it breaks in curves and concentric shells like glass. The fractures reveal smooth curved surfaces with no granular sparkle. Imitation stones like sodalite have more vitreous, granular fractures. Examining the fractured surface can help distinguish real vs. fake lapis.
Specific Gravity
The specific gravity of lapis lazuli ranges from 2.7-2.9. This means it feels noticeably dense and hefty for its size. Fake lapis made of plastic, resin, or glass often has a lower specific gravity around 2.4-2.6. Weighing a stone can determine if it has the requisite density of true lapis lazuli.
Fluorescence
Under ultraviolet light, lapis lazuli typically exhibits a weak chalky yellow or orangish fluorescence. This means it faintly glows this color under UV light. Plastics and resins fluoresce much brighter, while natural stones like sodalite do not fluoresce. Checking the fluorescence reaction can help authenticate lapis or reveal fakes.
Polish
Lapiz lazuli takes an excellent polish and maintains a vitreous luster. The surface should shine smoothly when polished, with no chalky or matte patches. Plastics and glass have an artificial translucency, while dyed stones often appear dull. The polish is a telling sign of a genuine or fake stone.
Durability
Lapis lazuli is relatively soft and fragile for a gemstone. It is vulnerable to pressure and impact. Avoid wearing lapis rings or bracelets to prevent chipping. Use caution when cleaning to prevent abrasion or fading. Lapis’ fragility is often mimicked in fake stones, but simulants like plastic lack the cold, stone-like feeling.
Price
Quality lapis lazuli has retained significant value throughout history. Lapis routinely sells for $50-100 per carat for high quality stones. Beware of stones in this price range sold as lapis that are likely fakes. Lower quality lapis can sell for as little as $2-10 per carat. The price can be a tip off for counterfeit stones.
Origin
The finest lapis lazuli historically comes from Afghanistan, Russia, Chile and India. The mines in Afghanistan have produced the most prized “azure blue” lapis for thousands of years. Reputable dealers should provide the geographic origin. Watch for stones merely labeled “imported” which are more likely to be fakes.
Inclusions
Most lapis lazuli contains small mineral inclusions of pyrite, calcite, or graphite. These minor imperfections indicate natural origin. Simulants like plastic or glass appear too perfect, clean, and uniform. Minor inconsistencies point to genuine lapis instead of manufactured stones.
Cut
Lapis lazuli is usually cut into cabochons, beads, or ornamental objects. The smooth domed cabochon cut provides an intriguing depth to the blue. Faceting or tumbled cuts are less common. Uniform factory-like cuts suggest man-made or simulated lapis lazuli.
Carat
Lapis lazuli stones typically range from just a few carats to around 50 carats for finer pieces. While lapis can grow in larger formations, stones above 75 carats should be inspected closely to ensure they are not fakes. Anything exceeding 100 carats is highly suspicious and probably not true lapis lazuli.
| Characteristic | Lapis Lazuli | Imitation Stones |
|---|---|---|
| Color | Rich, uniform blue | Too purple, gray or patchy |
| Flecks | Small pyrite flecks | None |
| Veining | Thin white calcite veins | None |
| Hardness | 5-6 can be scratched by steel | 7+ will not scratch as readily |
| Marbling | Delicate blue & white marbled pattern | None |
| Fracture | Conchoidal, curved break | Granular, vitreous |
| Specific Gravity | 2.7-2.9 dense and hefty | Less than 2.7 unnaturally light |
| Fluorescence | Weak, chalky yellow-orange | None or very bright |
| Polish | Smooth vitreous polish | Artificial glossy or matte |
| Durability | Soft, fragile, vulnerable to damage | Unnaturally hardy |
| Price | $50-100+ per carat for quality stones | Suspiciously cheap |
| Origin | Afghanistan, Chile, Russia | Vague or unknown |
| Inclusions | Minor inclusions typical | None, too clean and perfect |
| Cut | Cabochon, beads, ornate carvings | Faceted, tumbled, uniform |
| Carat | Up to 50 carats | Over 75 carats is suspicious |
Testing for Genuine Lapis Lazuli
The best way to test that a blue stone is real lapis lazuli is to subject it to a series of tests:
- Check the color for a rich, uniform blue without green or gray undertones
- Inspect for golden pyrite flecks throughout the stone
- Look for thin white calcite veining marbling the surface
- Try scratching with steel to see if it leaves an abrasion
- Examine the fracture for a curved, conchoidal profile
- Evaluate the hardness, density and feel in hand
- Verify fluorescence under UV light
- Note if the polish and luster appear natural
- Assess the price per carat and if it aligns with real lapis value
- Confirm the stone has some minor natural imperfections
By putting the blue stone through these validation checks, you can determine if it has the distinctive properties of true lapis lazuli or if it is an imitation. Pay attention to whether it passes the tests or if anomalies arise that indicate a fake. With knowledge and testing, identifying genuine lapis becomes much simpler.
Conclusion
Lapis lazuli is one of the most precious blue gemstones with a long history of use in jewelry and ornamentation. Distinguishing real lapis relies on verifying key characteristics like color, flecks, marbling, softness, fluorescence, and inclusions. By understanding how lapis looks and behaves, you can identify imitation stones attempting to copy this blue treasure. When shopping for lapis lazuli, go through a checklist of tests to validate each stone. This will ensure the blue gem you select is a true intense lapis lazuli rather than a fake substitution.