How about spessartine garnet?
After spessartine’s initial discovery and description in the Spessart Mountains of what was once Bavaria in 1832, it languished relatively unknown because of its scarcity. Many of the stones unearthed were dark orange with heavy brown modifiers, and only a few cut into gems of any noteworthy color. So it sat upon the pages of mineralogical manuscripts and collectors’ shelves for generations, unappreciated by the masses simply because they did not know about it.
Then a marvelous strike happened in Namibia in the 1990s. While this discovery didn’t drastically increase supply, these Namibian stones literally redefined what quality looked like in spessartine garnet.
The jewelry industry began to take notice of the vibrant tangerine orange gems coming from Southwest Africa. A few exquisite stones were faceted and made it into mainstream designs.
Then the dam really broke.
A massive lode was discovered in Nigeria a few years later. While few of those stones were of the pure spectral orange possessed by the Namibian material, the sheer volume of clean, facetable rough coming out of Nigeria was enough to make the orange garnet a much more common feature in jewelry. But some were pretty phenomenal.
Pass the manganese, please.
As with any colored gemstone, color is the coin of the realm with spessartine. Spessartine garnet is an idiochromatic gemstone, which means it owes its phenomenal color to nothing short of its own chemical makeup. Its manganese content is responsible for the purest oranges.
But like any other garnet, “spessartine” garnets always have some kind of mixture with another garnet species. Almandine is the most common mixture, and it’s the iron content of almandine that causes the reddish or brownish tones in spessartine from Madagascar, Nigeria, Brazil, and most other sources. Some stones from Nigeria are so pale they’re almost yellow. Others are so dark that you need a real direct beam of light to appreciate the color as you turn the gem in your hand.
There are also spessartine-pyrope mixes, that depending on the ratio, can be purple, pink, red, and even change color from blue to purple or green to brownish red.
What’s more, spessartine is one of the few gems to come by its beauty completely naturally, as there are presently no known treatments to improve its color or clarity. So if you’re looking for a gem you can be certain has not been enhanced, spessartine is one surefire way to go.
What to expect when shopping: Well, orange, obviously. But you’ll see a lot of reddish-orange and yellowish-orange, and maybe every once in a while a true, striking orange. Your preference for color is entirely subjective to you, but if you want a spessartine that looks like it was just picked off a tree in Florida, you can expect to pay for it. Generally, the purer and more intense the orange, the more valuable it is.
Fine Namibian spessartine is the most expensive, and stones of exceptional color from that source usually top out at around 5 carats, although I’ve never seen an excellent Namibian stone bigger than 4 carats. Spessartine from other sources can be cut to 15-20 carats with regularity, and I’ve seen fiery reddish-orange Nigerian gems even bigger than that.
Clarity is a relative term. Eye clean stones from California, Brazil, and Nigeria are common enough, but eye-clean stones from Namibia are a real rarity. Outside of Namibian material, the cleaner a stone, the more valuable it is considered.
Now, if there are too many inclusions, then yes, a stone will look too hazy and even opaque. But just the right amount can make mask extinction in cutting and scatter the return of orange light throughout the whole stone, almost making it glow.
To get another idea of what that effect is like, remember back to the last time you drove through a densely foggy night. Someone was approaching from the other direction, and the fog turned the other car’s headlights into a wall of light your eyesight couldn’t hope to penetrate. It’s the same optical effect.
Now imagine that wall of light is the purest, most vivid orange you can imagine. That is what fine Namibian spessartine garnet is like to look at in person.
But don’t let provenance color your judgment about an individual gem. Clean, vivid orange gems of world-class size have occurred from just about every major mine source of spessartine garnet, of which there are over a dozen.
As always, let the stone do the talking; let any paperwork supplement your appreciation, not define it.