Petrified Wood

Appearance, Uses and History

Petrified Wood is a fossilised form of wood in which the original organic material has been replaced by minerals – including chalcedony, agate, opal, coal, pyrite… the list is quite extensive. The majority of the fossilised wood on the market will be Silica based, though.

The process begins when a piece of wood or woody material is rapidly buried by mud or another wet sediment – this could be silt, volcanic ash, etc. The lack of oxygen slows the rotting of the wood, which allows various minerals to replace the wood over time. Volcanic ash is particularly known for producing petrified wood due to the large amounts of silica released.

Locales

Petrified Wood is found in a huge amount of locations worldwide; it occurs from the Devonian, when ‘woody’ plants first evolved, to almost the present day. I have found pieces of petrified wood in streams all over the country; it is often found in the form of Stigmaria, coal, or Jet, too.

Particularly large deposits of fossilised wood are found in numerous places – most sold online comes from Africa and Australia. Excellent quality specimens of Opalised wood can be found from Australia and Indonesia.

I would say it is fair to assume that some petrified or fossilised wood can be found in almost every country on Earth. A rarer phenomenon is a petrified forest – an area with a large amount of more complete wood in one area; sometimes this can be in the form of largely complete trees or standing logs.

There are numerous petrified forests in the USA, including the Petrified Forest National Park, the Ginkgo Petrified Forest State Park, the Gilboa Fossil Forest, the Mississippi Petrified Forest, the Yellowstone Petrified Forest, the Escalante Petrified Forest State Park, and the California Petrified Forest. However, there are fossilised forests in other countries too – Argentina, Australia, Brazil, Ecuador, Egypt, Germany, Georgia, Greece, India, Indonesia, Italy, Japan, Libya, Namibia, New Zealand, Thailand, Turkey, and the United Kingdom.

If you’re interested in visiting a local one and you’re a UK reader (most of you are!) – unfortunately, we don’t have anything quite as visually impressive as the American national parks. However, smaller areas can be visited around the UK at certain times. Some are on beaches and only visible with favourable conditions when a storm rips parts of the beach away, some are on private land.

• Glasgow, Scotland
• Lulworth, Dorset
• Whitby, Yorkshire (deposits of ‘Whitby Jet’ rather than a distinct forest)
• Wrexham, Wales

The UK also has numerous ‘submerged forests’; forests that have been buried under peat, sediment and water and well preserved for thousands of years. They are typically only visible from time to time when storms clear sand and peat from the beaches. These are often considered to be ‘sub-fossils’, partially fossilised specimens which either have not fully completed the fossilisation process or were buried in sub-optimal conditions.

• Bigbury Bay, Devon
• Borth, Ceredigion, Mid Wales
• Cleveleys, Lancashire
• Cley, Norfolk
• Daymer Bay, Cornwall
• Low Hauxley, Northumberland
• Penzance, Cornwall
• Portreath, Cornwall
• Redcar, Yorkshire
• Tywyn, Wales
• Ynyslas, Ceredigion, Mid Wales

Mineralogy

Hazards and Warnings

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

‘Petrified Wood’ is likely a term aimed directly at the English speaking market, so this section includes translations for ‘petrified wood’ and ‘fossilised wood’, and occasionally terms like ‘silicified wood’ or ‘silica replaced wood’.

Further Reading / External Links

• https://en.wikipedia.org/wiki/Petrified_wood
• https://geology.com/stories/13/petrified-wood/