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Barnebys HQ
Brahegatan 10
BOX 5038
114 37 Stockholm
All auctions / Ethnographical / Polished Blue Agate Geode Slice with Concentric Bands and...
This specimen comprises a remarkable section of Agate geode from Brazil, skillfully cut and polished to reveal its complex internal structure and mounted on a custom base. The piece fuses the raw beauty of mineralogy with the elegance of a design object, transforming a fragment of Earth's geological history into a sculpture of strong visual impact. The polished surface is a true natural painting. Concentric bands are observed, fading from translucent gray-blue to opaque milky white, creating a hypnotic and harmonious pattern. These growth lines tell the story of the slow deposition of silica inside the original volcanic cavity. At the center of the specimen, a sinuous cavity, or druse, is completely dotted with a multitude of microcrystals of quartz that shimmer with changes in light, adding a focal point and a brilliant texture. A particularly fascinating detail is the presence of an inclusion of another mineral, a gray-brown island surrounded by a green halo, which lends the piece a sense of uniqueness. The back of the specimen has been left in its natural state, showing the external, rugged crust of the geode. This surface, greenish in color and porous in appearance, provides a powerful material and chromatic contrast with the smoothness of the front side. This duality allows one to appreciate the piece in its entirety, from its original appearance to the beauty revealed by human craftsmanship. Agate geodes like this form inside volcanic rocks, mainly basalts. Gas bubbles trapped in the cooling lava create the cavities. Subsequently, for millions of years, silica-rich groundwater seep through the porous rock, slowly depositing layers of chalcedony (a microcrystalline variety of quartz) on the internal walls of the cavity. Variations in the water's chemical composition and the presence of trace elements determine the different colors of the bands. The remaining central cavity is often the place where, in a final phase, quartz has space to form larger and more defined crystals, as in the druse visible in this specimen. Thanks to its generous size, striking graphics, and presentation on a dark wood and brass pedestal, this piece transcends its status as a simple mineral for collection. It becomes a sophisticated decorative element, ideal for enriching a library, a study, or a contemporary setting. It is a perfect object for a modern Cabinet of Curiosities, capable of eliciting wonder and stimulating conversation, uniting scientific interest with a timeless sculptural aesthetic. Technical details Name: Agate Slice on Base Classification: Quartz, Chalcedony variety Provenance: Brazil Dimensions: 231 x 136 x 32 mm Weight: 1491 g Base: Included, wood and metal Condition: Good. The specimen retains its natural characteristics and the polishing on one side.
Estimate:£318.09
To the auctionView all items fromCatawikiorEthnographical
Estimate:
£318.09
OCT 17 | 10:00 PM
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