Spanish Sphalerite are fiery, cherry, lemon and tangerine gemstones from a famous deposit in the Picos de Europa in Northern Spain’s Iberian Peninsula, arguably the world’s premier source for fine Sphalerite. Spanish Sphalerite has a spellbinding brilliance, a fire over three times that of Diamond, and an adamantine (Diamond-like) luster, affording it a visual similarity to Fancy Diamonds, especially those with autumnal hues. Spanish Sphalerite’s flame throwing dispersion, coupled with its striking colors and extreme scarcity, make it an exclusive and exquisite addition to any exotic gemstone collection.
Hardness 3.5 – 4
Refractive Index 2.368 – 2.371
Relative Density 3.90 – 4.10
Enhancement None
Beauty
Coming in a beautiful array of citrus hues, Sphalerite is the most outstanding Spanish gemstone, and is highly regarded, especially in its premium qualities. As a rare exotic, Spanish Sphalerite is typically restricted to specialist collections and museum displays, even though it has some amazing Diamond-esque optical properties.
Fire, also known as dispersion, is the splitting of light into its component colors, and this gemological feature adds both beauty and value. While all gemstones of a large size exhibit fire, the most dispersive gemstones ranked in order are Sphene1, Demantoid2, Diamond3, and Zircon4. Sphalerite has more fire than all these (at 0.156 it is just over three times that of Sphene at 0.051), but as an exotic gemstone restricted to specialist collections, it is not included on most lists.
Sphalerite is brittle, difficult to polish, and also possesses six directions of perfect cleavage (easily exposed, continuous flat surface breaks that reflect light), making it challenging for the lapidary. While they can detract from brilliance, inclusions in Sphalerite can increase its fire. Our Spanish Sphalerite is very clean, and well-cut with excellent proportions, maximizing their signature brilliance.
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 sulphide, 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 is found in many countries including Australia, Bulgaria, China, Italy, Peru, Slovakia, and the USA, gem-quality specimens are exceedingly scarce with only two significant sources; Mexico’s Chivera Mine and Spain’s Picos de Europa.
Picos de Europa (‘Peaks of Europe’ in Spanish) 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 are many mines in the Picos de Europa, it is mined directly from host rock with gem-quality crystals typically small, noting Sphalerite over one carat demands a premium. Very rarely fashioned into gemstones, the extreme geological scarcity of gem-quality crystals is accentuated by faceting difficulties. Spanish Sphalerite is also a totally natural gemstone and not enhanced, further highlighting its rarity.
Durability & Care
An exotic jewelry gemstone (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
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