The image shows the centre of a polished slice of a petrified tree from Arizona. After enlargement of the image it is possible to see insect borings in the wood. They lived approximately 230 million years ago in the late <a href="https://en.wikipedia.org/wiki/Triassic" class="extiw" title="w:Triassic">Triassic</a>. Size: 15.34cm × 18.04cm
<a href="//commons.wikimedia.org/wiki/User:Michael_G%C3%A4bler" title="User:Michael Gäbler">Michael Gäbler</a>
CC BY 3.0
Self-made Scan with "Epson Perfection 4490 Photo" from the middle part (size 15,34 × 18,04 cm) of a polished slice of petrified wood from Arizona. This file is large enough to make a fine print.