7.4" Agate Nodule w/ Amethyst on Metal Stand - Brazil

This is a gorgeous nodule of agate from Brazil with an amethyst and quartz crystal pocket. It has been cut and polished on one side, retaining a natural look on the reverse face. The agate features blue, white, and cream banding.

This nodule sits snuggly on a custom metal display stand that is removable with considerable effort, thought this is not recommended.

Agate is a translucent variety of microcrystalline quartz. Agate primarily forms when silica-rich fluids fill pockets within rock and/or fossils, resulting in deposition of the silica along the walls of the rock. This process can result in banding patterns as the composition and impurities of the fluids change over time. These banding patterns can either form as flat layers or rounded layers, depending on the surfaces available for deposition.

Agate has also been known to fill veins or cracks in volcanic rock. Such agates, when cut transversely, exhibit a succession of parallel line giving a banded appearance to the section. Such stones are known as banded agate, riband agate and striped agate.

The agates from Brazil are mined from decomposed volcanic ash and basalt from the late Permian age (248-275 million years old) In Rio Grande do Sul the "agate mines" are normally just plowed fields in which loose agates are found and collected. These agates can be very colorful and polish beautifully.
FOR SALE
$195
DETAILS
SPECIES
Chalcedony var. Agate & Quartz var. Amethyst
LOCATION
Brazil
SIZE
7.4 x 6.3" (without base), about 4.4" thick, 9.9" tall on stand
CATEGORY
SUB CATEGORY
ITEM
#216848