Peristerite Gemstone: Properties, Meanings, Value & More

Peristerite is a gemstone in the feldspar family known for displaying an iridescent quality sometimes called “schiller.” It can also display adularescence, an internal glow most famous in moonstone.

The stone is mainly known from Canada, like labradorite and perthite. Peristerite isn’t necessarily rare, but it’s less common than labradorite.

In this guide, we’ll go over peristerite’s meaning, prices, history, and more, including how it compares to moonstone and labradorite.

Pictured above: Iridescent peristerite-oligoclase feldspar from Russia labeled as "moonstone" | Image credit: James St. John, Flickr, CC-BY-SA-2.0

What Is A Peristerite Stone?

Peristerite is a lesser-known semi-precious gemstone in the feldspar family. Many mineralogists classify it as an albite variety, though it contains other feldspars, too.

One trade name for peristerite is “belomorite,” applied to Russian peristerites from the White Sea area, called Beloe More in Russian.

The gem is known for displaying iridescence or adularescence, latter leading to the monikers for peristerite “pierre de lune” (French) and “albite moonstone.”

We’ll cover more about peristerite vs moonstone later. But as a moonstone-like gem, peristerite can serve as a June birthstone, Cancer zodiac stone, and 3rd wedding anniversary gem.

Peristerite Specifications & Characteristics

Within the feldspar family, there are two main groups: alkali (potassium) and plagioclase. All feldspars are aluminum silicates, but the major element at the beginning of their formulas differs.

Alkali feldspars range from microcline (potassium-dominant; KAlSi3O8) to albite (sodium-dominant; NaAlSi3O8).

Plagioclase feldspars have a mixture of anorthite (calcium-dominant; CaAl2Si2O8) and albite in different ratios. As you can see, albite is technically in both groups.

Peristerite is in the plagioclase series.

The official plagioclase varieties are:

• Albite: 0 to 10% anorthite, 90 to 100% albite

• Oligoclase: 10 to 30% anorthite, 70 to 90% albite

• Andesine: 30 to 50% anorthite, 50 to 70% albite

• Labradorite: 50 to 70% anorthite, 30 to 50% albite

• Bytownite: 70 to 90% anorthite, 10 to 30% albite

• Anorthite: 90 to 100% anorthite, 0 to 10% albite

Peristerite is considered an albite variety by many, but it can be between albite and oligoclase. The stone can be about 75 to 99 percent albite and 1 to 25 percent anorthite — in other words, an albite:anorthite ratio of 99:1 to 75:25.

Usually, peristerite contains layers of both albite and oligoclase. Crystals may exhibit albite twinning or pericline twinning.

Peristerite Properties Listed:

• Mohs hardness: 6-6.5

• Color: Light blue, light green, red, brownish-red, tan, white, gray, colorless; Iridescence - white or blue

• Crystal structure: Triclinic

• Luster: Vitreous or sub-vitreous; May be pearly on cleavages

• Transparency: Transparent to opaque

• Refractive index: 1.531-1.550

• Density: 2.60-2.67

• Cleavage: Perfect on [001] , distinct/good on [010], imperfect/poor on {110}

• Fracture: Conchoidal, irregular/uneven, or splintery

• Streak: White

• Luminescence: None

• Pleochroism: None

• Birefringence: 0.007-0.011

• Dispersion: Weak to none

• Optical effects: Iridescence, adularescence

Pictured above: Piece of persiterite found in Central Ontario in summer 2021 | Image credit: MrSkullduggeryJones, Reddit

Peristerite vs Similar Feldspar Gems

The colorful optical effects — be it iridescence or adularescence — in feldspar gems like peristerite and labradorite are caused by the same phenomenon.

This phenomenon is a type of optical interference, where light reflects from different structures inside the stone. These structures are thin layers (lamellae) of plagioclase feldspars. The feldspar layers have different thicknesses and compositions.

The way these layers are intergrown and layered cause light to reflect differently, since the layers have different refractive indices, resulting in the gorgeous schiller.

Despite these similarities, peristerite still differs from these similar feldspar gems.

Peristerite vs Labradorite

Pictured above: Spectrolite (labradorite variety) drilled pendant

Labradorite and peristerite look very similar, but the iridescence in peristerite — sometimes called peristerescence — is usually more “delicate” (lighter in color) than the labradorescence seen in labradorite.

Plus, labradorite’s iridescence can have more colors than peristerite. One labradorite variety called spectrolite has iridescence in every color.

Compositionally, labradorite has more anorthite and less albite than peristerite.

Peristerite vs Moonstone

Pictured above: Adularescent, faceted moonstone

Is peristerite a moonstone? Technically, peristerite could be called moonstone because “moonstone” is a trade name for feldspars with adularescence (a milky internal glow).

Many gemologists define moonstones as orthoclase varieties with alternating orthoclase and albite layers. But others define moonstones as having orthoclase or oligoclase with albite, meaning peristerite (which has oligoclase and albite layers) could fall under the definition.

Focusing on the stone at hand, what is the spiritual meaning of peristerite?

Peristerite Meaning & History

Peristerite symbolizes clarity, serenity, and stability.

Many of its meanings are similar to those of moonstone: peace, compassion, and romance.

Peristerite also reflects the metaphysical attributes of labradorite: transformation, determination, and resilience.

History

The name “peristerite” derives from the Greek term peristera, meaning “pigeon,” because the stone’s iridescence matches that of many pigeons’ neck feathers.

Peristerite was first discovered in Canada in the 1840s by two physicians who also happened to be amateur mineralogists and mineral collectors. These men were Dr. James Wilson and Dr. Andrew Fernando (A.F.) Holmes.

It’s unclear where in Canada Holmes’ specimens came from, but we know that Wilson’s came from present-day Lanark County. Holmes labeled his specimens “iridescent felspar” (an old spelling of feldspar).

Both physicians sent their samples to Dr. Thomas Thomson, a chemistry professor at the University of Glasgow. Thomson analyzed the stones and published his analysis in 1843, naming them “peristerite.”

In the same article, Thomson wrote the first description of perthite, another feldspar from Canada sent to him by Dr. James Wilson.

Shifting to the metaphysical, what are the healing properties of peristerite?

Peristerite Healing Properties

As a popularly blue healing stone, peristerite has similar metaphysical properties of other blue gemstones, offering serenity, truth, and reflection. It can also be used as a throat or third eye chakra stone.

Physical Healing

Physically, peristerite is believed to treat issues related to:

• Cognitive function

• Vision or eye disorders

• High blood pressure

• Reproductive health

• Menstrual pain

• Indigestion

Emotional Healing

Crystal healers recommend peristerite for enhancing intuition and opening yourself up to greater opportunities.

The crystal can encourage honest self-reflection so you can understand what you truly want, who you truly are, and how you can embrace change to achieve your desires.

Additionally, peristerite is said to promote resilience, helping you move toward the future even when the past is trying to pull you back.

Pictured above: Faceted moonstone

Peristerite Gemstone Properties

Peristerite’s value depends on its color (including optical effects), cut, clarity, transparency, and carat weight.

Color

Though peristerite’s base color can vary, the best peristerite specimens are colorless with strong iridescence, as many peristerites have weaker iridescence. The stone’s iridescence ranges from white to blue, with vibrant blue iridescence being most valuable.

Any strongly adularescent specimens also carry high value.

Cut

Most gem-quality peristerites are cut into cabochons, which can somewhat range in shape. Another common choice is carving, like crystal points or towers, for instance.

Sometimes the stone is faceted, but this is rarer.

Many peristerites for sale are rough (uncut).

Clarity & Transparency

Clarity describes the degree of visible inclusions in a gem, which can lower its transparency and value. The most valuable peristerite is fully transparent, though most top-quality specimens are only semi-transparent.

Potential inclusions in peristerite include:

• Tourmaline

• Vermiculite crystals

• Non-homogenous growth patterns

• Fingerprints, sometimes with two-phase inclusions

Carat Weight & Size

Peristerite gem material can be found and cut in huge sizes. Most cabochons for sale are over 40 carats, and carvings can be over 400 carats.

Pictured above: Close-up of iridescent peristerite-oligoclase feldspar from Russia labeled as "moonstone" | Image credit: James St. John, Flickr, CC-BY-SA-2.0

Peristerite Formation & Sources

Plagioclase feldspars like peristerite often form in rocks that underwent metamorphism. The type, stage, or region of metamorphism can lead to different feldspars. Peristerite is found in rocks with a metamorphic grade between greenschist and almandine amphibolite facies.

Peristerites with a composition closer to albite may be found in igneous rocks like pegmatites, basalts, and greenschists.

Minerals commonly associated with peristerite include schorl (black tourmaline), biotite, muscovite, nepheline, and augite.

Mining Locations

The best source of peristerite gem material is Ontario, Canada. Another major source is Kenya, specifically Kioo Hill.

Other sources of peristerite are:

• China

• Mexico

• Norway

• Russia

• Spain

• USA (Connecticut, Maine, Michigan, New York, Pennsylvania)

Adularescent peristerite (often labeled “albite moonstone” is known from China and Pennsylvania (USA).

Pictured above: Peristerite specimens from Perth, Ontario, Canada, displayed at Matheson House Museum | Image credit: Sam_0532, blogspot

Peristerite Price & Value

Luckily, peristerite is a pretty affordable gem and often lower in price than moonstone.

Because peristerite is rarer than labradorite, it may be slightly more expensive, but the higher demand for (and familiarity with) labradorite may make its prices higher than the price of peristerite.

Peristerite cabochons cost around $0.50 to $3 per carat or roughly $35 to $130 total.

You can find peristerite carvings, usually large crystal points over 300 carats, for under $0.10 per carat or roughly $30 to $60 each.

Peristerite necklaces are generally $35 to $50 each.

Peristerite Care and Maintenance

More good news: gemstone care for peristerite is pretty easy!

The one consideration is its perfect cleavage, so peristerite jewelry should have protective settings (particularly rings) and avoid sharp blows to the stone.

You can clean peristerite with the standard warm water, mild soap, and a soft toothbrush. Don’t keep it submerged in water for long periods of time.

Paint Your Future Under Peristerite’s Glow!

Peristerite may not be as familiar as labradorite or moonstone, but it’s just more humble! This feldspar gem brings a soft yet powerful energy perfect for looking toward the future with positivity and hope.

Buy peristerite and other great gemstones today!