Pseudomorphosis (by substitution) is the phenomenon by which a mineral presents itself under the appearance of another mineral (the shape of the tree is preserved). The original substance is gradually replaced by a different substance, without chemical reactions: the silica replaces, molecule by molecule, the fibre of the wood, producing the silicified wood, also called petrified wood. The percolation fluids from exposed sediments dissolve the soluble components (calcite, pyrite or silica) drive them from the surface to a certain depth where they are reprecitated.

These exchanges take place under certain conditions of temperature and more or less high pressure, still without the crystal form being modified, but to the benefit of the most stable minerals, for example: pyritisation, dolomitisation, silicification or opalisation. They are called metasomatosis.



One slab, one page of a unique history

A plaque cut from a trunk reveals a unique pattern, with colourations giving the appearance of liquid colours which have set. The trunk's patterns and colours evolve between its base and its top, but quite often, a tree presents a chromosomal unity. Its colours are the result of its own structure and its own journey. Each cut reveals its story, its characteristics, and study of this helps to understand the various stages.



Under the microscope

Certain areas of petrified wood are translucent. One can see into the material (up to a depth of 5mm).

It is possible to distinguish, under the microscope, the partitions in the ligneous cells. They are usually of a colour distinct from that which is set within the cell, by reason of a succession of stages throughout petrifying.

The use of a microscope also allows for an extraordinary journey into a three-dimensional world, where it is possible to recognise cells characteristic to a type of wood, micro crystallisations and unique aesthetic details.



A surprising alliance

Ash, water and wood, via an unbelievable alchemy, have formed an alliance in order to produce trees made out of silica, one of the hardest stones on our planet. Water, a tree and ash were needed for this miracle. The soil surrounding the trees did not become quartz, it remained as ash.

On a scale from 1 (Talc) to 10 (diamond) silicified trees, hardness level 7, are situated between granite and precious stones.



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