Petrified wood slice from Arizona with a lot of milky opal

A petrified wood slice from Arizona with a high proportion of milk opal. The opalescent SiO₂ background highlights the growth rings as a high-contrast relief, making the piece a paleobotanical collector's cut.

Petrified wood from Arizona comes from the Triassic Chinle Formation (approx. 225 million years ago). Quartz-containing solutions replaced the wood structure cell by cell, preserving growth rings, vascular bundles, and medullary rays 1:1. Milk opal, as an amorphous SiO₂ variant, fills the remaining spaces with whitish-opalescent mineralization.

The combination of agate-quartz plus milk opal is classified in the collector's trade as a gemmologically high-quality multi-component petrification. The opalescent component increases the material value beyond standard wood cuts.

Such Arizona cuts are paleontological documents: each growth ring corresponds to a growth year of a Triassic tree, each mineralization zone to a geological phase. The polish brings out the stratigraphy.

A paleobotanical collector's item with multi-component genesis and premium material classification.