Exhibit of the month 3 / 2021
A sample of fossilized wood from the Vršany quarry.
The fossil is 15 to 20 million years old and originates from the Middle Miocene epoch.
In the mining area of the Vršany quarry, parts of fossilized trees are found during the extraction of overburden layers. Pieces of these trees are often found in the quarry's spoil heaps, where they weather out from the upper layers of transported overburden rocks.
Entomologist OMGM Pavel Krásenský discovered an interesting sample of fossilized wood at one of the reclaimed spoil heaps during his research. It is a piece measuring 12x17x22 centimeters. The wood has a rather uncommon brownish coloration for this location. Its surface features hundreds of millimeter-sized quartz crystals in charred layers. Similar, black-colored samples with quartz crystals were once abundant in the Bílina quarry. Quartz in these woods most commonly occurs in two forms – crystal and smoky quartz. Very often, the crystals are doubly terminated. The small crystals have a high luster and reflect light significantly, which is why geologists referred to them as "sparkling stones." Currently, finds of "sparkling stones" are rare.
The fossilized wood from Vršany has very well-visible growth rings in the original wood. Another peculiarity is the preserved stump of a branch at the edge of the wood.
Text: Pavel Dvořák
Photo: Pavel Krásenský