The image above of opalised wood has been making the rounds on Facebook recently, with some users asking if it’s real. So we endeavoured to find out what it is and where it comes from.
What you see above is petrified wood, that is formed when plant material is buried by sediment and protected from oxygen and organisms. As water runs down through the earth, it gathers silica and filters into the cracks or porous areas of the wood. The water eventually evaporates, and leaves behind a silica deposit. This process repeats until the build-up of silica fills up the spaces completely, becoming opal.
Opal, unlike amethyst or diamonds, does not have an ordered microscopic structure that forms a crystal lattice. Instead, these gemstone comprise of round or lumpy silica balls that refract light, making it colourful and giving it that quintessential opalescent sheen. The colour of the opal is dictated by the diameter and spacing of the silica balls. Smaller silica balls have blue hues, while larger silica balls have red hues. The intensity of the colour depends on the uniformity of the silica.
This image and the video of the opalised wood (see video below) was originally posted by Sean, the shop owner of PlanetOpal, in 2012. The videos are created to show off Australian opals and other products up for sale.
Image and video credit: Sean, PlanetOpal