What is petrified wood?
We regularly receive surprised questions from passersby at trade shows: "Is this wood? Or stone?" The answer to this frequently asked question can be found below.
Petrified wood is one of nature's most fascinating materials. It combines the beauty of wood with the hardness of stone and tells a story that is millions of years old. Xyleia Petrified Wood We work daily with these special fossils, originating from Indonesia – especially from the islands Java en SumatraIn this blog post, we explain exactly what petrified wood is, how it is formed, and where it is found.
What exactly is petrified wood?
Petrified wood – also known as fossil wood This is called wood that has been completely mineralized. This means that the original organic material of a tree has been replaced by minerals over millions of years, while the shape, grain structure, and details of the original wood have been preserved. You can still clearly see the grain direction, growth patterns, and sometimes even the bark, but the material has turned into stone.
How is petrified wood formed? The chemical process
The process by which wood petrifies is called permineralizationThis happens under specific geological conditions, often after a volcanic eruption:
- Death and covering of the wood
A tree dies and falls. Shortly after, it is quickly covered by volcanic ash, mud, or sediment. This layer blocks oxygen, preventing the wood from rotting. - Effect of mineral-rich water
Groundwater, rich in dissolved oxygen, seeps through the volcanic ash layers silicon dioxide (SiO₂), often in the form of silicic acid (H₄SiO₄). This mineral-rich water penetrates the wood through the cellular openings. In this phase, permineralization location: the porous wood is penetrated by silica, without the organic structure immediately disappearing. - Crystallization and replacement of the wood
The organic material in the wood gradually dissolves. Minerals derived from the silica precipitate in the vacated spaces. Depending on the chemical conditions (such as temperature, pH, and ionic composition), the silica forms crystalline or amorphous minerals such as chalcedony, agate, jasper, or opal. This process of crystallization and complete replacement of the original wood can take millions of years, resulting in a fossil in which the wood structure is faithfully preserved, yet composed entirely of stone. - Result: an exact stone copy of the wood
What ultimately remains is a stone in which the entire wood structure is still visible – but without any organic material present. It is fossilized wood in its purest form.
Where does petrified wood come from?
Petrified wood is found worldwide in places where volcanic activity has occurred in the past. Some well-known areas include:
- Arizona (US)
Petrified Forest National Park is home to numerous fossil trees over 200 million years old (Jurassic period). Red is the dominant color here. - Madagascar
Here one finds colorful petrified wood, often with many iron and opal inclusions, which give it vibrant hues. - Indonesia – Java and Sumatra
Indonesia is rich in volcanic activity and has vast areas where petrified wood is found. Java en Sumatra Much fossil wood was formed between 15 and 23 million years ago, during periods of intense geological activity.
At Xyleia Petrified Wood All the fossilized wood comes from these Indonesian regions. The natural conditions there ensure exceptionally well-preserved structures and characteristic earth tones in the fossilized wood.
The colors of Indonesian petrified wood
During the separate blog we will discuss the colours and why petrified wood can change colour.
And finally
Petrified wood is a natural phenomenon created by a subtle interplay of time, minerals, and geological processes. What was once a living tree, through millions of years of slow transformation, becomes a stone that looks like wood—but is as hard as quartz. It is a tangible reminder of a prehistoric landscape, shaped by volcanoes, ash, and minerals.
At Xyleia we have a deep appreciation for this material. In a next blog we will tell you more about the applications of petrified wood in the interior – from coffee tables to washbasins.