14.5" Agate/Mineral Replaced Petrified Wood - Tom Minor Basin, Montana

This is a 14.5" wide slab of a petrified wood cast from the Tom Miner Basin area of Montana. While not technically petrified wood, it's created when the the organic material is destroyed and the void is filled in with silica (agate) and other minerals. The slab has been polished to a glossy finish on one side and comes out of an old collection.

This piece is exceptionally beautiful when backlit as it's transparent in spots and the many layers present from multiple deposition events can be seen. There are repaired cracks through this specimen. Comes with a display stand.

Petrified wood is the name given to wood that has been turned into stone (fossilized) through the process of permineralization. In this process, all of the organic matter becomes replaced by minerals, while much of the original structure, such as tree rings, is retained. For this to happen, the wood needs to be buried in an environment low in oxygen to prevent decomposition and with flowing, mineral-laden water, so minerals may replace structures. The coloration is caused by various minerals that present in that water during fossilization. For example, red colors are due to iron compounds, greens due to copper, and so on.

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 rocks and/or fossils, depositing the silica along the walls of the rock. This process can result in banding patterns, as the compositions and impurities of these depositing fluids change over time. These banding patterns can either form as flat layers, creating linear patterns known as waterline agate, or as rounded layers, forming more common ring-like patterns. These patterns depend on the surfaces available for deposition.
Tom Miner Basin, Montana
14.5" wide, 11.7" tall, 1" thick
We guarantee the authenticity of all of our
specimens. Read more about our
Authenticity Guarantee.