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Rare, Gem-Quality Fairburn Agates

Rare, Gem-Quality Fairburn Agates

Limited Availability: These singular specimens were acquired as part of a private museum closure this year. Once they are gone, they will be gone forever.

Shaped for jewelry or simply polished for ornamental display, the mesmerizing swirls and patterns of agate rock formations have been cherished by humans for millennia. In a word, they are enchanting.

Above: The Fairburn round nodule in hand.

Agates typically form as nodules within a host rock as superheated silicates invade cavities, settle, and then cool. Layer after layer, these deposits form unique shapes and patterns with vibrant colors. The process of agatization can be applied to nearly any host formation, including fossils though more typically it occurs in volcanic or metamorphic rocks.

About: Rough agates from the same region. No idea what might be inside until they are cut and polished, but typically less than 10% will display gem-quality banding. From that small selection, only a handful will appear like these specimens.

As you might expect, agates come in innumerable varieties. They are usually named for their location and the process of their formation.

Above: Close-up of a section of 6.2" slab displaying the Foritifaction Agate banding.

Fairburn Agates are a rare example of Fortification Agate, a type of agate characterized by sharp-edged bands that resemble castle fortifications viewed from above. Their distinctive bands of chalcedony are colorized by trace minerals such as iron oxide and hematite (along with many others). 

Above: The 3-in-1 5.8" Slab displaying three different and distinct agate patterns in a single piece.

Fairburn’s have wide and distinctive bands. They take their name from the town of Fairburn, South Dakota. They are held in high regard by collectors and are the official state gemstone of South Dakota.

Above: The Fairburn round nodule with classic banding. This piece measures roughly 4.5" x 4.2" x 3".

The individual, gem-quality specimens in the Mini Museum collection come from “Teepee Canyon” (also known as Hell’s Canyon). The Minnelusa Formation limestone in this region dates to the Late Carboniferous Period (Pennsylvanian) and Early Permian Period, roughly 300,000,000 years ago. At that time, the land known today as South Dakota was covered by a shallow sea.

Above: An exterior view of one-half of the 3.9" paired specimen. Both of these specimens exhibit a natural exterior surface with polished inner faces. 

The agates were previously held by a private museum in Custer, South Dakota for many decades and recently deaccessioned. The area is now closed to new mining making these particular specimens rarer still.

Above: The 4.8" slab. One side is polished and the reverse side has rough agate peeking through the natural Minnelusa limestone surface.

As shown, these specimens exhibit the classic Fairburn patterns with rich colors running from bands of reds, browns, and orange to blue, black, yellow, and white. The specimens will ship in sturdy cartons and will also include a full-size Mini Museum Certificate of Authenticity.

Above: Half of the 3.8" matched pair in hand.

Fairburn Agate Descriptions:

  • 4.8" Rough/Polished Slab - A single polished face and a rough face to highlight the refined and natural state of this orange and black agate.
  • 6.2" Polished Slab - Large and intricate, this piece features two polished sides. Orange bands accent the bluish-white center and intricate patterns. 
  • 3.9" Matched Pair - Cut from a single agate nodule, this paired specimen includes two polished faces and preserves the natural exterior. Orange and yellow are the dominant colors.
  • 5.8" 3-In-1 Slab - Both sides are smooth-polished to highlight the three separate agate nodules within. Orange and black are the dominant colors.
  • 4.5" Large Nodule - Smooth-polished large nodule with a concave, unpolished bottom. It measures roughly  4.5" x 4.2" x 3". Striking red and white banding with a small crystal hollow. It is hefty.

Please Note: Due to the unique nature of these agates, each piece is sold individually and once they are gone they are unlikely to return.

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