Petrified palmwood

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Petrified palmwood
Conservation status: Fossil

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Liliopsida
Order:	Arecales
Family:	Arecaceae
Genus:	Palmoxylon

Species

See text

Petrified palmwood (Palmoxylon sp.), is the state stone of Texas and the official state fossil of Louisiana. It is from the Oligocene epoch (34 - 23 mya) and can be collected from many scattered sites in east Texas and western Louisiana. Palmoxylon is the genus designated for petrified trunks of palm. Fossils found near fossil palmwood include corals, sponges, and mollusks. This is because the palms grew along prehistoric beaches. For millions of years, the shoreline has been moving farther south.

Petrified Palm wood is a group of fossil woods that contain prominent rod-like structures within the regular grain of the silicified wood. Depending upon the angle at which they are cut by fracture, these rod-like structures show up as spots, tapering rods, or continuous lines. The rod-like structures are sclerenchyma bundles that comprise part of the woody tissues that gave the wood its vertical strength. Petrified palm wood is a favorite of rock collectors because it is replaced by silica and exhibits well-defined rod-like structures and variety of colors. As a result, it exhibits a wide range of colors and designs when cut that can be incorporated into jewelry and other ornamental items. Because it is composed of silica, it is hard enough to polish and withstand the wear and tear of normal use.

In Texas and Louisiana, petrified palmwood is most common in the Toledo Bend area, which is shared by both states. It was left by trees that grew when the Gulf of Mexico's shoreline was much farther north from its present day position. In Louisiana, petrified palmwood is found in the parishes of Rapides, Natchitoches, and Sabine.

Though the trees that left these fossils have long been extinct, many other kinds of palms are still living.

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