4.15" Las Choyas "Coconut" Geode Half with Agate & Amethyst - Mexico

This is a beautiful "coconut geode" half from Chihuahua, Mexico. This geode half is filled with banded agate and a smoky amethyst crystal encrusted cavity near the center. It has been cut flat and polished to a glossy finish. Only the pictured half of this geode is included.

Comes with an acrylic display stand.

Geodes are rounded, hollow voids in rocks filled with crystals and other minerals. They are typically formed when air bubbles inside of volcanic rock form hollow cavities. Over time, as mineral-rich water seeps into the rock it beings to deposit tiny crystals on the sides the hollow cavity. After millions of years, the flow of water gradually builds crystals inside the empty space.

Las Choyas geodes, often referred to as coconut geodes are mined from 100 to 200 feet below the surface near Chihuahua, Mexico. Shafts are drilled down to the geode bearing white clay, and then tunnels are dug horizontally to extract the geodes.

The geodes typically range from about 2-6 inches in diameter and can contain a variety of minerals and crystals. Most hollow geodes contain a variety of quartz ranging from clear quartz to smoky quartz to more rarely amethyst. Many secondary minerals such a goethite, hematite, mordenite, calcite and galena may also be present in some geodes.

Agate is a variety of microcrystalline quartz (chalcedony) that displays translucence and in some cases banding. 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.

Amethyst is a purple variety of quartz (SiO2) and owes its violet color to natural irradiation, iron impurities, and the presence of trace elements, which result in complex crystal lattice substitutions. It’s considered a semi-precious gemstone, and just two centuries ago was considered to have a value on par with diamonds, sapphires and rubies. The largest and best known amethyst deposits occur in southern Brazil and Uruguay but many localities around the world produce an amazing variety of amethyst crystals and formations.

DETAILS
SPECIES
Chalcedony var. Agate & Quartz var. Smoky Amethyst
LOCATION
Chihuahua, Mexico
SIZE
4.15" wide
CATEGORY
SUB CATEGORY
ITEM
#180556