Purpurite Value, Price, and Jewelry Information

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11.21-ct purpurite, pear-shape cabochon, Namibia. Photo courtesy of liveauctioneers.com and Jasper52.

Purpurite is too soft for jewelry wear and never transparent. Nevertheless, lapidaries have cut cabochons from this material with magnificent purplish rose hues.

Purpurite Information

Data Value
Name Purpurite
Formula (Mn,Fe)PO4
Colors Deep rose to reddish purple; alters on outside to brown or black.
Fracture Uneven
Hardness 4-4.5
Cleavage Good 1 direction
Crystallography Orthorhombic. Crystals rare, in small masses and cleavages.
Refractive Index 1.85-1.92
Birefringence 0.007
Dispersion Very strong
Luminescence None
Luminescence Present No
Absorption Spectrum Not diagnostic
Pleochroism Strong: gray/rose-red or deep red/purplish red.
Optics a = 1.85; β = 1.86; γ = 1.92. Biaxial (+), 2V moderate.
Optic Sign Biaxial +
Luster Dull, satiny.
Specific Gravity 3.69
Enhancements Acid etching
Transparency Translucent to opaque
Etymology After the Latin purpura for "purple," in allusion to the color.
Occurrence A secondary mineral, due to the oxidation of phosphates in granite pegmatites.
purpurites - Namibia

Purpurites (about 2 inches across), Usakos, Namibia. Photo © Joel E. Arem, PhD, FGA. Used with permission.

What is Purpurite?

Purpurite forms a mineral series as the manganese-dominant (Mn) end member to the iron-dominant (Fe) end member heterosite. Both end members have similar colors and properties, but purpurites occur far more rarely than heterosites.

heterosite - Maine

Heterosite, 11.7 x 5.4 x 5.4 cm, Newry, Oxford Co., Maine, USA. © Rob Lavinsky, www.iRocks.com. Used with permission.

How Can You Distinguish Purpurite from Sugilite and Charoite?

Sugilites and charoites can look like purpurites and show the same purple colors. Keep in mind that purpurite is the rarest of these three gem materials and is also the least likely to be found cabbed or carved.

Despite appearances, there are numerous differences between these materials. Purpurite has a much higher, over-the-limit refractive index. Physically, purpurite has a softer hardness (4-4.5) than sugilite (6-6.5) and charoite (5-6) as well as a purple streak. Sugilite and charoite have white streaks. However, scratch and streak tests aren’t recommended for finished gemstones.

The easiest way to distinguish these gems is a specific gravity (SG) test. Purpurite has a much greater SG value (3.69) than sugilite (2.74) and charoite (2.54-2.78).

Is There Any Synthetic Purpurite?

Scientists have synthesized purpurites for mineralogical research. However, despite purpurite’s rarity and attractive color, it’s unlikely there is any consumer demand for this lab-created material. This gemstone is too little known to generate much of a market and too soft for jewelry wear.

Mineral specimens may receive acid treatments to enhance their purple color.

purpurite mass on quartz

A purpurite mass on quartz, lightly treated with oxalic acid to brighten it. Brown Thurston prospect, Rumford, Oxford County, Maine, USA. Photo by Douglas Watts. Licensed under CC By 3.0.

Where are Purpurites Found?

Usakos, Namibia produces rich, purplish masses in abundance and at low cost. Most gem-quality material comes from this location.

Other notable sources include the following

  • United States: California; Maine; North Carolina; South Dakota.
  • Western Australia; France; Portugal.
purpurite - Portugal

Purpurite on matrix, Bendada Mine, Bendada, Sabugal, Guarda, Portugal. Photo by Pascal Ollic. Public Domain.

Stone Sizes

Cabochons up to several inches long can be cut from cleavages.

How to Care for Purpurites

Avoid cleaning purpurites with mechanical cleaning systems, like steam and ultrasound. Clean these gemstones only with a soft brush, mild detergent, and warm water. Consult our gemstone jewelry cleaning guide for more care recommendations.

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