Slaughter Mountain Fire Agate Rough – Cabinet Specimen with Natural Gem SLM070

Up for sale is a classic untouched fire agate rough specimen from the world famous Slaughter Mountain gemstone deposit in Arizona. This collector grade piece features a stunning exposed botryoidal fire agate gem cluster of iridescent chalcedony displaying a natural play of color caused by alternating layers of silica and iron oxides. The gemstone formation sits perfectly on its original brecciated rhyolite host rock, beautifully contrasted by pockets of rich carnelian chalcedony and crystalline druzy quartz. It is an exceptional display piece, or a high grade piece of carving rough, for mineral enthusiasts looking for top tier Arizona material.

The photos shown represent the actual specimen you will receive, photographed both outdoors in natural sunlight and indoors under full spectrum artificial light. The stone is displayed dry as well as wet to simulate a polished appearance for optimal visual display.

This item with be packaged and shipped with extreme care to ensure all fragile botryoidal and druzy structures arrive intact.

Specimen Metrics & Dimensions

Weight: 98.1 Grams (Approx. 3.46 oz)

Dimensions: 2-¾ inches x 2-½ inches x 1-¼ inches

Matrix: Solid, structurally stable, brecciated rhyolite host rock

Geological & Aesthetic Highlights

This specimen displays a textbook paragenetic sequence typical of fire agates forming within volcanic cavities. It showcases a distinct combination of hydrothermal silica phases and host rock matrix, making it an excellent teaching or display specimen for mineral collectors. This piece serves a triple purpose: it is a stunning natural cabinet specimen, an educational paragenetic display, and an elite tier lapidary rough piece with massive hidden value.

This rough piece beautifully showcases a textbook volcanic vug sequence. The top portion features an exposed, highly contoured botryoidal cluster of iridescent fire agate. These microcrystalline bubbles display a vibrant play of color (Schiller effect) caused by thin film light interference across alternating layers of silica and iron oxide platelets (goethite and limonite).

Complementing the main specimen formation is a distinct, deep reddish brown carnelian chalcedony nodule nestled in a central cavity, framed by pockets of shimmering macrocrystalline druzy quartz and common milky chalcedony. The 1-¼ inch matrix depth provides solid, reliable anchoring for safe handling or lapidary clamping.

Lapidary & Carving Potential

For lapidary artists and master carvers, this specimen offers an extraordinary opportunity. The geometry of the top botryoidal formation runs deep. Preliminary evaluation indicates that with skilled, meticulous contour carving, this piece holds the potential of yielding a large, finished multi-colored Fire Agate gemstone. With flashes of bright colors resting just beneath the surface layers, the finished gem yield alone carries immense retail potential.

Locality Provenance

This specimen originates from Slaughter Mountain, Arizona, an area celebrated for fire agate gemstones displaying vivid color ranges such as bright reds, oranges, deep greens, purples, and rare blues. The deposit lies within the San Carlos Apache Indian Reservation where mining rights are exclusively held by tribal members. Due to very limited mining activities at Slaughter Mountain, uncut fire agate rough specimens of this nature are becoming extremely rare and hard to obtain. Purchased directly from the San Carlos Apache miners in 2012 the authenticity of this specimen display is guaranteed.

Detailed Mineralogical & Geological Information

The Fire Agate Gemstone Formation

Morphology: The upper portion features a prominent, exposed botryoidal (grape like) cluster of chalcedony bubbles. This structure formed as silica rich fluids coated the interior walls of a volcanic vug in successive, concentric layers.

Optical Phenomena & Composition

A subtle, multicolored iridescence (Schiller effect) is visible across portions of the bubbly surfaces. This play of color is a result of thin film interference. During the Tertiary Period, hydrothermal fluids alternatingly deposited ultra thin layers of silica and iron oxide platelets (primarily goethite or limonite). These microscopic layers refract and diffract light, shifting colors as the specimen is rotated.

Chalcedony & Agate Variations

Cryptocrystalline chalcedony (milky, translucent, and carnelian).

Carnelian Chalcedony: Nestled within a central pocket is a distinct, smooth, reddish brown chalcedony nodule. Its rich coloration is due to higher concentrations of evenly dispersed iron oxide impurities within the silica lattice, trending into the carnelian variety.

Common Chalcedony: Surrounding the primary fire agate formations are smaller pockets of white to translucent, non iridescent chalcedony. These represent periods of hydrothermal precipitation where iron oxide levels dropped, leaving behind clean microcrystalline chalcedony.

Crystalline Quartz Base

Crystalline druzy quartz lining underlying cavities. Deep within the fractured recesses and framing the chalcedony, fine grains of macrocrystalline druzy quartz are visible. This represents a distinct phase in the cooling sequence when fluid flow slowed and temperatures stabilized, silica grew as defined, with micro-pointed quartz crystals rather than fibrous chalcedony aggregates.

Rhyolite Host Rock Matrix

Matrix host rock is an altered, vesicular rhyolite (Tertiary volcanic origin). The structural backbone of the entire specimen consists of a porous, light tan to reddish rhyolite host rock. This fine grained igneous matrix is highly typical of the volcanic fields in the southwestern United States. The rough, brecciated appearance indicates that gas bubbles (vesicles) and tectonic fractures within the cooled lava created the open pathways necessary for the mineral rich fluids to deposit this complex sequence of silica millions of years ago.

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