Lawsonite Gemstone: Properties, Meanings, Value & More
Lawsonite (pronounced LAH-suh-nyte) is a commonly colorless, gray, or light blue mineral known for its importance in geological research. In recent times, green chromium lawsonite has come to the gemstone market.
In terms of rarity, the mineral itself is fairly rare and lawsonite gemstones are extremely rare.
How do I identify lawsonite? It’s important to know its properties, which we’ll cover in this guide.
Today, we’ll go over lawsonite’s mineral traits, gemstone properties, prices, history, and more!
Pictured above: Faceted chromian lawsonite gemstone from Greece, 1.5 carats | Image credit: Kay Günther / G-Empire The World of Gems / http://www.g-empire.de/
What Is A Lawsonite Stone?
Lawsonite is a very rare semi-precious gemstone, often seen in green, mottled gemstones on the market.
It’s important not to mix up lawsonite with larsonite. “Larsonite” is a trade term for a gemstone composed of petrified bogwood formed from silica fluids going through rhyolite ash and forming jasper as a byproduct. It has vibrant patterns and colors.
Other trade names for larsonite are “gary green jasper,” “caldera jasper,” and “McDermitt bog agate.” Notably, jasper is a chalcedony variety with an entirely different composition to lawsonite.
Unlike jasper, lawsonite is better known for its non-gemstone uses.
Lawsonite Uses
Lawsonite is an important mineral in geology. For one, its presence in a rock indicates the rock formed under high-pressure (and usually low-temperature) conditions, often where oceanic crust sinks down oceanic trenches into Earth’s mantle.
Additionally, lawsonite’s structure holds a considerable amount of water, though prograde metamorphism causes lawsonite to lose a lot of this water and transform into denser, less hydrous (or anhydrous) minerals. That means it can carry water down very deep underground (mantle level).
As such, geologists have experimented on lawsonite’s reactions to various pressure and temperature levels to see how well it can still carry that water down under different conditions.
This research can also help geologists learn more about how the rocks (where lawsonite is found) form and transform (metamorphose) over time.
Lawsonite has also been used by researchers for harvesting dew through radiative cooling.
Pictured above: Glaucophane grains in retrogressed metabasalt from Elba Island containing lawsonite, blue glaucophane grain with actinolite rims surrounded by chlorite, green actinolite, tiny high-relief epidote grains, and large brown clinopyroxene relics; Researched for representing some of the highest pressure products of early continental underplaying in the Northern Apennines | Image credit: Samuele Papeschi, CC-BY-SA-3.0
Lawsonite Specifications & Characteristics
As a hydrous calcium aluminum hydroxide sorosilicate mineral, lawsonite’s formula is CaAl2(Si2O7)(OH)2·H2O. Chromium is a potential impurity.
Although lawsonite is related to the epidote mineral group, it’s in the lawsonite mineral group. The lawsonite group also includes:
Amamoorite
Cortesognoite
Hennomartinite
Ilvaite
Itogawaite
Manganilvaite
Noelbensonite
Manganilvaite and amamoorite are monoclinic, while the rest are orthorhombic. Lawsonite is the aluminum endmember in a series with cortesognoite (the vanadium endmember).
From the feldspar group, anorthite is nearly lawsonite’s anhydrous (no water) equivalent. However, the two minerals’ aluminum structures and densities differ.
Lawsonite crystals are usually prismatic or tabular, though it can also occur in granular or massive habits. Lamellar twinning for lawsonite is common.
Here are lawsonite’s properties listed:
Mohs hardness: 6-7.5
Color: Usually colorless, white, gray, grayish-blue, or light blue; Can be yellow, blue-green, yellow-green, green, or peachy pink; Rarely reddish-brown
Crystal structure: Orthorhombic
Luster: Vitreous or greasy
Transparency: Translucent or transparent
Refractive index: 1.665-1.686
Density: 3.05-3.12
Cleavage: Perfect on {001} and {010}, poor on {110}
Fracture: Irregular/uneven
Streak: White
Luminescence: None
Pleochroism: Sometimes present - blue or pale brownish-yellow to deep blue-green, yellow-green, or yellow to colorless or pale yellow
Birefringence: 0.019-0.021
Dispersion: High
Optical effects: Very rarely chatoyancy
Pictured above: Two elongated, translucent, pastel pink lawsonite crystals embedded in a mica schist from original California type locality; John Ydren collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Lawsonite History
The first recorded discovery of lawsonite happened in California, USA. British-born American geologist Frederick Leslie Ransome and American mineralogist and crystallographer Charles Palache described the new stone in 1895.
Ransome and Palache decided to name the stone “lawsonite” after their geology professor at the University of California, Berkeley, Scots-born Canadian geologist Andrew Cowper Lawson.
In 2003, the Gemological Institute of America (GIA) first encountered lawsonite as reddish-brown or “root beer” colored inclusions in a polished Guatemalan jade disk.
The first time the GIA examined cut and polished lawsonite was in 2008, when Steve Perry of Steve Perry Gems gave them some faceted and cabbed lawsonites.
Around 2011 to 2012, green chromium-bearing lawsonite entered the market. However, some of the “chromian lawsonite” minerals available, reportedly mined from a locale in Syros, Greece, turned out to be coated lawsonite pseudomorphs.
Lawsonite Healing Properties
As a popularly blue healing stone, lawsonite joins other blue gemstones in promoting serenity and harmony. Colorless lawsonite crystals can be crown chakra stones, like other white gemstones.
Physical Healing
Physically, lawsonite is believed to help with issues related to:
Kidneys
Nightmares
Insomnia
Immune system
Respiratory health
Emotional Healing
Emotionally, lawsonite crystals are believed to help you harness your thoughts to be at peace rather than controlled by negative emotions like anger or anxiety. It’s also associated with emotional balance and rejuvenation.
Pictured above: Lawsonite crystals from Mitani, Kochi City, Kochi Prefecture (translated from Japanese) | Image credit: D. Nishio-Hamane, Flickr, CC-BY-SA-2.0
Lawsonite Gemstone Properties
Beyond its rarity, lawsonite’s value as a gemstone also depends on its color, cut, clarity, transparency, carat weight, and treatments.
Color
Most lawsonite crystals are colorless, white, or pale shades of blue to gray, so any brighter hues will carry higher value. Strong pleochroic colors will also raise lawsonite’s value. In thin sections, lawsonite is usually colorless.
Many faceted lawsonite gems for sale online contain chromium and other elements. These lawsonites’ colors are almost always mottled, with varying shades of green, along with orange, black, and/or yellow.
Cut
Not only does the rarity of facetable material make faceted lawsonites extremely rare, but lawsonite’s cleavage (perfect in 2 directions) makes the stone quite difficult to cut.
The collection of faceted and cabbed (cut en cabochon) gems examined by the GIA in 2008 — mentioned in the History section above — came from a 320-kilogram collection of specimens consisting of under 0.1 percent facetable material. Steve Perry was able to cut 11 carats of faceted stones and 110 carats of cabochons.
Clarity & Transparency
Clarity describes the degree of visible inclusions in a gemstone. More visible inclusions means lower transparency and usually, lower value. The majority of lawsonite specimens are opaque and highly included, so translucent to transparent specimens carry high value.
In the collection from Steve Perry, most were translucent to opaque. The chatoyancy seen in around 5 percent of his cabochons may have been due to inclusions.
GIA found the following inclusions in all of Perry’s lawsonite gems:
Crystals
Clouds
Feathers
Fingerprints
Because lawsonite is brittle, it may also contain cavities and chips.
Carat Weight & Size
Lawsonite gemstones are typically 2 to 3 carats large at the maximum, with most much smaller than that. Transparency will also decrease in larger sizes. For instance, in Steve Perry’s collection, the largest transparent faceted lawsonite was 0.40 carat.
Treatments & Simulants
As mentioned in the History section, some “chromian lawsonite” gems are actually lawsonite pseudomorphs, meaning a new mineral that replaced lawsonite but retained lawsonite’s crystal structure.
Plus, these pseudomorphs had artificial coatings to give them their green color, making them technically lawsonite simulants. These coatings could be removed with acetone.
Speaking of mineral replacement, how is lawsonite formed?
Pictured above: Glaucophane-lawsonite metamorphite (bluschist) from California, USA with bluish-black acicular glaucophane masses and light-colored lawsonite | Image credit: James St. John, CC-BY-SA-2.0
Lawsonite Formation & Sources
Lawsonite minerals characteristically form in metamorphic rocks under high-pressure, low-temperature conditions. These conditions are often in subduction zones, where tectonic plates converge, with one going under the other to sink down into the Earth’s mantle.
One type of rock found in these zones is blueschist, specifically blueschist facies, which contain lawsonite, garnet, epidote, jadeite, and glaucophane. Blueschist facies turn into eclogite facies at depths greater than 60km, and eclogites can also contain lawsonite but this is more rare.
Lawsonite is also found in altered gabbro rocks, diorites, and jadeitites.
Common minerals associated with lawsonite are:
Mining Locations
Facetable lawsonite crystals have almost solely been found in California, USA.
Other important sources of lawsonite specimens include:
Celebes Island
China
Cuba
France
Italy
Japan
New Caledonia
New Zealand
Turkey
The mineral is also found along the Pacific Ring of Fire, the nickname for the circum-Pacific orogenic belt.
Pictured above: Pale blue lawsonite crystal specimen from California, USA; Jungles Collection via Tom Loomis | Image credit: Kelly Nash, CC-BY-SA-3.0
Lawsonite Price & Value
Colorless faceted lawsonite gemstones are generally the priciest and hardest to come by. These stones are around $4,100 to $5,700 per carat, though the actual price will usually be much lower (around $250 to $340) because the carat weights are quite low, often under 0.5 carats.
Truly chromium-bearing lawsonite rough specimens can be pricey as well, up to $1,150.
Other lawsonite rough is significantly lower, around $50 to $150 each.
Faceted “chromium-bearing lawsonite” online — which may be a mixture of lawsonite and other minerals or a coated pseudomorph — ranges from about $15 to $30 per carat or about $60 to $100 each.
You can find lawsonite pendants for around $20.
Lawsonite Care and Maintenance
Last up is gemstone care. Lawsonite is relatively easy to care for, but you have to be careful of its perfect cleavage, as a sharp blow could break it.
As such, you may want protective settings on lawsonite jewelry, particularly rings.
You can clean lawsonite with the standard warm water, mild soap, and a soft toothbrush.
Looking for a Lawsonite of Your Own?
Lawsonite is an important mineral for geology, but a rare find in the gem world, making any cut lawsonite gem or attractive rough crystal a fantastic find!
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