“Scapolite,” 49.2 cts, golden yellow cut-corner modified emerald brilliant cut, Tanzania. © Rob Lavinsky, www.iRocks.com. Cropped to show detail. Used with permission.
Although not well known, scapolite would make an attractive gem material for both jewelry enthusiasts and mineral collectors. It comes in a wide variety of colors and can show dramatic fluorescence. Rare specimens also display phenomenal effects, like chatoyancy.
Yellow scapolite’s value depends on size, clarity, and strength of color. Expect the usual premiums on price in terms of color saturation and custom versus native or commercial cutting. Values for natural purple or violet scapolites differ greatly from irradiated stones, since the untreated stones are rarer and have a delicate, but much purer, purple. Prices for untreated purple stones would exceed yellow, while prices for irradiated purple stones fall below yellow.
Rare cat’s eye scapolites are highly varied and quite beautiful.
Cabochons cut from opaque Quebec and Ontario material are very lovely and often fluoresce brightly.
Tanzanian golden scapolite is much darker in tone than the Brazilian material, as well as much cleaner. Moreover, there is enough available to make jewelry promotion feasible.
Scapolite: Brazil (24.0) and Kenya (2.30). © Joel E. Arem, PhD, FGA. Used with permission.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
| Gold | 1 to 3 carats | 3 carats plus |
| Faceted | to /ct | to /ct |
| Purple | .5 to 1 carat | 1 carat plus |
| Faceted | to /ct | to /ct |
| Colorless | 1 to 10 carats | 10 carats plus |
| Faceted | to /ct | to /ct |
| Cat’s Eye | 1 to 10 carats |
| to /ct |
| Star | 1 carat plus |
| to /ct |
| Data | Value |
|---|---|
| Name | Scapolite |
| Varieties | Marialite, Meionite, Petschite, Wernerite |
| Colors | Colorless, white, bluish gray, pale greenish yellow, pink, violet, brown, orangey brown, golden yellow, orangey yellow. |
| Crystallography | Tetragonal; crystals prismatic, often large and coarse; massive, granular, cleavages. |
| Refractive Index | Varies by composition and locality, 1.531-1.600. See “Identifying Characteristics” below. |
| Luster | Vitreous; resinous; pearly on cleavages. |
| Polish Luster | Vitreous, resinous |
| Fracture Luster | Vitreous, resinous, pearly |
| Hardness | 5.5-6 |
| Wearability | Poor |
| Fracture | Uneven to Conchoidal |
| Specific Gravity | 2.50-2.78, varies with composition. See “Identifying Characteristics” below. |
| Birefringence | Varies by composition and locality, 0.004-0.037. See “Identifying Characteristics” below. |
| Cleavage | Perfect/distinct in two directions |
| Dispersion | 0.017 |
| Luminescence | Myanmar: yellow to orange in LW (U spectrum), also pink in SW. Tanzania: strong yellow in both LW, SW; violet stones = pink in SW, inert in LW. Quebec: massive material fluoresces in LW (+ phosphorescence). Some yellow faceted gems fluoresce lilac in SW. Strong orange in X-rays. |
| Luminescence Present | Yes |
| Luminescence Type | Fluorescent, Phosphorescent, UV-Long, UV-Short, X-ray Colors |
| Enhancements | Heat treatment, improves color, common, undetectable. Irradiation turns colorless and yellow to purple. Uncommon, fades rapidly. |
| Typical Treatments | Heat Treatment, Irradiation |
| Special Care Instructions | Avoid rough handling |
| Transparency | Transparent to Opaque |
| Absorption Spectrum | Pink and violet stones show bands in the red at 6630 and 6520 due to Cr. Strong absorption in the yellow part of the spectrum. |
| Phenomena | Very rare: chatoyancy, iridescence, tenebrescence, aventurescence. |
| Formula |
|
| Pleochroism |
|
| Optics |
Uniaxial (-). |
| Optic Sign | Uniaxial - |
| Etymology |
Scapolite comes from the Greek skapos for “shaft,” because of the stumpy nature of its prismatic crystals. Marialite was named after Maria Rosa, wife of German mineralogist G. vom Rath. Meionite comes from the Greek meion for “less,” because its pyramidal form is smaller than that of idocrase from Vesuvius, which it resembles. Mizzonite comes from the Greek meizon for “greater,” because the axial ratio is larger than that of meionite. Wernerite was named after the mineralogist Abraham Gottlob Werner. |
| Occurrence |
In contact zones; regionally metamorphosed rocks; altered basic igneous rocks. |
| Inclusions |
Hollow tubes, needles, platelets. |
Scapolite: Tanzania (32.44, 32.00). © Joel E. Arem, PhD, FGA. Used with permission.
The scapolite mineral group contains a solid state series from marialite to meionite, with mizzonite as the intermediate member. Gemologically speaking, the term scapolite refers to the gems that form in this series. (Older sources may refer to this series as wernerite). The colors and properties of scapolites vary as the amount of sodium and calcium in their chemical composition changes.
Colors range from near colorless through pinks and purples to yellow and orange. By far, yellows occur most commonly. Purples come a distant second.
Scapolites may show strong fluorescence and pleochroic colors. In addition, rare specimens have displayed a variety of phenomenal effects. These include chatoyancy (in many colors and with unusually sharp “eyes”) and tenebrescence.
Cat’s Eye Scapolite: Myanmar (7.0). © Joel E. Arem, PhD, FGA. Used with permission.
In addition, so-called “rainbow scapolites” display iridescence. Recently, the Gemological Institute of America (GIA) found that brownish orange platelets, possibly hematite inclusions, caused aventurescence in a scapolite specimen. (Be aware that pink scapolite with sheen is sometimes erroneously called pink moonstone).
“Rosalinda,” an ornamental laidary rock from Peru, consists of calcite, scapolite, and red epidote-piedmontite.
Under shortwave ultraviolet light, this tenebrescent colorless scapolite changes to a light blue. Over time, the blue fades back to colorless. “Scapolite,” cushion cut, 1.55-ct, 7.6 × 7.4 ×5.0, Pakistan. © ARK Rare Gems. Used with permission.
Distinguishing citrines, a yellow variety of quartz, from yellow scapolites may sometimes prove challenging (without a destructive scratch test). Consult this article on difficult separations for advice.
Scapolite: Kenya (73.31, crystal ca 3 inches long). © Joel E. Arem, PhD, FGA. Used with permission.
| Locality |
Color |
o |
e |
Birefringence |
Specific Gravity |
| Marialite |
– |
1.546-1.550 |
1.540-1.541 |
0.004-0.008 |
2.50-2.62 |
| Entire Rios, Mozambique |
yellow |
1.568 |
1.548 |
0.02 |
2.70 |
| Umba River, Tanzania |
yellow-gold |
1.562-1.567 |
1.543-1.548 |
0.019 |
2.66-2.67 |
| Umba River, Tanzania |
violet |
1.539-1.540 |
1.531-1.534 |
0.007 |
2.59 |
| Umba River, Tanzania |
yellow |
1.553 |
1.539 |
0.014 |
2.63 |
| Umba River, Tanzania |
very pale yellow |
1.579 |
1.553 |
0.026 |
2.74 |
| Rio Pardo, Brazil |
golden yellow |
1.570-1.574 |
1.549-1.552 |
0.021 |
2.68-2.70 |
| Myanmar |
colorless |
1.56 |
1.544 |
0.016 |
– |
| Myanmar |
pink |
1.558 |
1.545 |
0.013 |
– |
| Myanmar |
light yellow |
1.587 |
1.554 |
0.033 |
– |
| Myanmar |
pale pink |
1.549 |
1.54 |
0.009 |
2.63 |
| Myanmar (cat’s eye) |
violet |
1.560 |
1.544 |
0.016 |
2.63 |
| Sri Lanka (cat’s eye) |
gray |
1.583 |
1.553 |
0.030 |
– |
| Kenya (cat’s eye) |
brown |
1.57 |
– |
2.73 |
|
| Madagascar |
colorless |
1.568-1.571 |
1.550-1.552 |
0.018-0.020 |
– |
| Meionite |
– |
1.590-1.600 |
1.556-1.562 |
0.024-0.037 |
2.78 |
Refractive index (RI) and birefringence (δ) as related to chemical composition in the scapolite series. Chemistry expressed as (molecular) percent meionite, which reflects the ratio Ca/(Ca + Na) in the formula. Refractive index plotted as a mean index = (o + e)/2. Adapted from W. A. Deer, R. A. Howie, and J. Zussman, 1962, The Rock Forming Minerals, vol. 4 (New York: Wiley), p. 329.
Note: Dipyre is a Ca-rich marialite.
“Fluorescent Wernerite,” Grenville, Quebec, Canada, from the collection of the Technische Universität Bergakademie, Freiberg, Germany, by SpacePen. Licensed under CC By-SA 3.0.
Scientists have synthesized scapolites, from marialites to meionites, for research purposes. However, there are no known jewelry uses for these synthetic materials.
Heating can improve color. This common enhancement is undetectable.
Yellow and colorless scapolites may receive radiation treatments. This uncommon enhancement creates a brownish purple color, which fades rapidly.
Tanzania produces the finest golden yellow scapolite known in commercial quantities. Dodoma, Tanzania yields transparent, golden yellow to orangey yellow gem material. This source sometimes produces very pale to near colorless stones, as well as violetish and pink (rare) cuttable crystals.
Espirito Santo, Brazil produces pale yellow crystals, sometimes large and facetable.
Madagascar produces yellow, facetable crystals.
Other notable gem-quality sources include:
“Scapolite,” four crystals from Daftar, Tashiku’ergan Co., Kashi Prefecture, Xinjiang Autonomous Region, China. © Rob Lavinsky, www.iRocks.com. Used with permission.
The pink and purple Tanzanian material is extremely rare in sizes over 5 carats. You’ll find most gems of this color in the 1-2 carat range.
Brazilian yellow scapolite is cuttable up to about 30 carats. However, at that size, it’s usually flawed (long thin tubes).
Faceted Myanmar scapolites are rarely encountered on the market. However, white and yellow specimens from Myanmar have been found in large sizes. Pink Myanmar step-cut gems to 70 carats have been reported. Cat’s eyes usually run under 10 carats. However, larger ones are known.
Scapolite: Myanmar (6.65), Brazil (5.77), Kenya (1.93), Myanmar (9.0). © Joel E. Arem, PhD, FGA. Used with permission.
With a hardness of 5.5 to 6 and perfect cleavage, scapolites require care when setting and wearing as jewelry. Although daily wear as a ring stone may be inadvisable, protective settings and occasional use will let you show off these rarely seen gems. Scapolites would make excellent choices for pendants and earrings. Avoid cleaning them with mechanical systems. Instead, use only a soft brush, mild detergent, and warm water. Consult our gemstone jewelry cleaning guide for more recommendations.
“Primrose Earrings,” golden citrine globes, pale yellow scapolite rondelles, and clear rock crystal rondelles, by Marianne Madden. Licensed under CC By-SA 2.0.
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