Pumpkin Obsidian and Peanut Obsidian

What are pumpkin obsidian and peanut obsidian?

These are two varieties of black obsidian marked by rounded, pale-colored clusters scattered through the volcanic glass.

Pumpkin obsidian, obsidiana calabaza in Spanish, shows orange to reddish-brown zones and speckles on a dark background. The comparison to a squash rind is immediate, hence the name.

Peanut obsidian, obsidiana cacahuate, shows beige, light gray, or pale brown clusters, often grouped in twos or threes, whose shape and tone bring to mind peanut shells scattered over black.

Both names come from Mexican quarries and remain little known outside the collector market. See where they sit among the others in my guide to obsidian varieties.

The shared secret: spherulites

Here's the piece of information almost no site gives you, and it explains everything: the patches in both varieties are spherulites.

A spherulite is a cluster of fibrous crystals arranged in rays, which grew outward from a single point, like a tiny ball of down. Here's the mechanism.

Obsidian is glass: the lava cooled so fast its atoms never had time to arrange into crystals. But this glass sits in a metastable state, it "wants" to crystallize. If the temperature stays high enough for long enough, or if a flaw offers a starting point, crystallization kicks off locally.

It then grows radiating outward from that point, forming a sphere of mineral fibers, usually feldspar and cristobalite. Unlike the glass, these crystals are opaque and pale: they show up as light patches on the black.

This process is called devitrification: the glass turns back, in places, into a crystalline rock. To understand how obsidian is born, see my article on how obsidian is formed.

The snowflake family

You already know this mechanism, even if you didn't realize it. It's exactly the one behind snowflake obsidian, whose white blooms are also cristobalite spherulites.

Pumpkin, peanut, and snowflake obsidian are therefore all one geological family: the spherulitic obsidians. What sets them apart isn't their nature or how they form, but three variables.

Color depends on the crystal composition and the iron oxides present: white for pure cristobalite, beige to orange once iron gets mixed in. Size depends on how much time was available for growth: the slower the cooling, the more room the spherulites had to grow larger.

Pumpkin or peanut: how to decide

Honestly, the line is blurry and depends a lot on the seller. Two clues still hold up.

The first clue, then, is color: warm for pumpkin, neutral for peanut. The second is coverage: pumpkin tends toward large patches, peanut toward isolated spots.

A single flow can produce both, and a stone somewhere in between will be sold under one name or the other depending on the quarry worker's mood. As with peacock obsidian, these are trade names, not mineralogical categories.

The meaning attributed to these varieties

Worth saying, as with other recently named varieties: there's no ancient tradition specific to pumpkin or peanut obsidian. The current correspondences were formulated by analogy with their appearance.

They're generally credited with:

• grounding and protection, qualities shared by all obsidians;
• warmth and comfort for pumpkin, by analogy with its autumnal tones;
• balance and patience for peanut, in line with snowflake obsidian, whose structure it shares;
• inner growth: a correspondence that follows nicely from the geology, since spherulites are literally crystals that grew inside frozen matter.

As for chakras, they're linked to the root chakra like any obsidian, and pumpkin sometimes to the sacral chakra for its orange tones. The full picture is in my guide to obsidian and chakras.

If these warm tones appeal to you, mahogany obsidian offers a similar palette, reddish brown, with much better availability, and it's what I actually make in my studio.

Spotting and buying

Good news: these varieties are rarely faked, simply because demand and prices are low. The main risk isn't a fake stone, but a dyed stone or a made-up name.

• Spherulites should show a slight relief, under raking light, you can spot a very slight difference in level between the polished glass and the crystallized zones, which are softer and sit slightly recessed;
• Edges should look diffuse, a spherulite blends gradually into the glass. A sharp, regular outline is a sign of dye or printing;
• Distribution should be irregular, patches spaced too evenly are suspect;
• Watch out for neon orange, natural pumpkin obsidian stays in earthy tones, never garish.

On price, these varieties rank among the most affordable obsidians, on par with snowflake obsidian. A high price isn't justified by rarity here. My benchmarks are in obsidian pricing and value.

One technical point worth knowing: since spherulites are softer than the surrounding glass, they polish less evenly. A stone with large spherulites often shows a slightly uneven polish, that's not a manufacturing flaw, it's the nature of the material.

Mineral data sheet

Care and cleansing

One specific precaution applies here, tied to structure: spherulites are softer and slightly more porous than the glass around them.

• Avoid soaking, water can seep into the crystallized zones;
• Cleaning, a soft, dry cloth is best. If needed, a quick rinse under clear water, then dry immediately;
• Cleansing, smudging works perfectly, since it avoids any liquid contact. Never use salt, which gets lodged in the spherulites;
• Recharging, moonlight, without prolonged sun exposure;
• Abrasion, never scrub with a sponge or a rough microfiber: you'd wear down the spherulites faster than the glass, pitting the polish.

Full step-by-step care is in my guides to cleaning obsidian and cleansing and recharging.

Frequently asked questions