Showcasing fiery, cherries, lemons and tangerines, Spanish Sphalerite are from a famous, and now largely historic, deposit in Spain’s Picos de Europa (Peaks of Europe), arguably the world’s premier source. Spanish Sphalerite’s fire is over three times that of Diamond, yet it’s far rarer, with a spellbinding brilliance and an adamantine (Diamond-like) luster, combining to afford a visual similarity to Fancy Diamonds. With commercial mining halting 35 years ago, Spanish Sphalerite’s flame throwing dispersion, striking colors and ever-increasing scarcity, makes it a truly exclusive and exquisite, exotic gemstone.
Hardness 3.5 – 4
Refractive Index 2.368 – 2.371
Relative Density 3.90 – 4.10
Enhancement None
Beauty
Coming in a gorgeous array of citrus hues, Sphalerite is the most outstanding Spanish gemstone, and highly regarded for its amazing Diamond-like characteristics and premium quality. Our Spanish Sphalerite beautifully displays, bright oranges, reds, and yellows with a highly-desirable medium saturation (strength of color) and tone (lightness or darkness of color), the marketplace ideal. As a rare exotic, Spanish Sphalerite is typically restricted to specialist collections and museum displays, even though it has some remarkable optical properties.
Fire, also known as dispersion, is the splitting of light into its component colors, with this gemological feature adding both beauty and value. While all gemstones of a large size exhibit fire, Sphalerite (0.156) is the world’s most dispersive gemstone, followed by Demantoid/Andradite (0.057), Cerussite (0.055), Sphene (0.051), Diamond (0.044) and Zircon (0.039). Sphalerite has almost three times more fire than the second most dispersive gemstone, Demantoid, but as an exotic gem restricted to specialist collections, Sphalerite (and Cerussite) aren’t included on most lists. Sphalerite also has an excellent brilliance (refractive index 2.368 – 2.371, just below Diamond 2.417 – 2.419, the most brilliant gemstone), good transparency, extreme scintillation (‘play of light’ or sparkle), and an adamantine (diamond-like) luster, beautifully reflecting a high percentage of surface light.
Brittle, difficult to polish, and possessing six directions of perfect cleavage (easily exposed, continuous flat surface breaks that reflect light), Sphalerite is challenging for the cutter. While they can detract from brilliance, inclusions in Sphalerite can increase its fire. Optimally faceted by experienced French and Ceylonese (Sri Lankan) lapidaries who carefully orientate each crystal to maximize their signature fiery brilliance, maintaining a high-polish/luster, and an attractive overall appearance (outline, profile, proportions and shape), our Spanish Sphalerite is very clean, displaying exceptional clarity for the type. Similar to Emerald, Sphalerite is classified as a Type III gemstone by the GIA (Gemological Institute of America), gemstones that typically grow with many inclusions in nature, which are usually eye-visible. Our Sphalerite clarities range from eye-clean (the highest quality clarity grade for colored gemstones as determined by the world’s leading gemological laboratories) to moderately included (minor inclusions visible to the unaided eye).
Sphalerite, also known as Blende or Zinc Blende, gets its name from the Greek ‘sphaleros’ (treacherous) in allusion to the historic ease with which dark mineral varieties were mistaken for galena (the most important lead ore mineral). Similarly, ‘blende’ is from the German for ‘blind’ or ‘deceiving’. Sphalerite consists largely of crystalline zinc sulfide, but almost always contains variable iron. The more iron, the darker and opaque the gem. The mineral is almost always nearly black in color, but it is occasionally found in transparent pieces that are facet grade. Sphalerite occurs in a wide range of colors, including bluish-green, brown, colorless, green, orange, red, yellow, and yellowish-green. However, most gem-quality crystals are canary, cherry, crimson, honey, lemon, tangerine or verdant, with its red hues being the rarest; clear red crystals are also colloquially known as ‘Ruby Blende’.
Rarity
While mineral Sphalerite’s found in many countries including, Australia, Bulgaria, China, Italy, Peru, Slovakia, and the USA, gem-quality crystals are exceedingly scarce. Mexico’s Chivera Mine and Spain’s Picos de Europa, are the two most significant sources, but these are no longer actively mined. Worked since the Middle Ages, Bulgaria’s Madan Ore Field in the Rhodope Mountains is still yielding mineral specimens, with broken transparent, gemmy crystals used for cutting. Unlike Spain’s Sphalerite deposits during their peak production in the 80s, the Huanggang mines in Inner Mongolia are limited and sporadic. Fine Yellow Sphalerites are mined in upstate New York in the Balmat area, northeast of Fort Drum, but these quantities are also minuscule.
Picos de Europa are in Northern Spain’s Iberian Peninsula and form part of the Cantabrian Mountains. The most widely-accepted origin for ‘Picos de Europa’ is that they were the first sight of Europe for ships arriving from America. The Picos de Europa is a range of mountains some 20 kilometers inland from the northern coast of Spain, covering three different Autonomous Regions and several municipalities. While there were many mines in the Picos de Europa, it’s extracted directly from host rock with transparent crystals typically small; Sphalerite over one carat demands a premium. The esteemed Aliva Mine, which closed in 1989, and Las Manforas Mine are world-famous for their transparent crystals in beautiful colors including, reddish-orange and orange to yellow/orange, orange/brown, and yellow. With mining ostensibly halting in the late 80s, the area was turned into a National Park in 1995, negating future commercial activity. Some amateur, hobbyist collectors are still trying to fossick mineral specimens and occasionally, gem-quality crystals, but the quantity’s insignificant, especially when compared to its historic mining.
With availability dependent on depleting reserves, crystals available for faceting, are challenging to source, especially in finer qualities in larger sizes. Some old crystals still remain here and there, but increasingly less and less. Very rarely fashioned into gemstones, and hardly ever set in jewelry, the extreme geological and marketplace scarcity of gem-quality crystals is complicated by faceting difficulties. Spanish Sphalerite is also totally natural and unenhanced, accentuating desirability, rarity, and value.
Durability & Care
An exotic jewelry gemstone perfect for special occasions (Mohs’ Hardness: 3.5 – 4), Spanish Sphalerite should always be stored carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.
Map Location
Click map to enlarge
