FMF - Friends of Minerals Forum, discussion and message board

[lluis]

Hi, Pierre

Wood could be impregnated in salt solutions and become breakable in short time.
From that, to to have a silica pseudo wood, is another history.
A silica pseudo wood took many time.(simply organic matter should gone....and that take its time)
A copper pseudo wood, far less.
Two processes, two speeds...

But a true "petrified wood" took more time..
And trials, well, if wire has survived, then it is low saline and just a salt impregnated wood.
Done for fire proof trials at beginning last century (the XXth....)

With best wishes

Lluís

[alfredo]

The speed with which the organic matter in wood disappears is astonishingly variable, depending on conditions. In a tropical rainforest, wood might be gone in 6 months. On Axel Heiberg island there is Eocene wood (~ 40 million years old) that is still burnable and not mineralized!

[lluis]

Yes, Alberto...
But in a rain forest, bacteria are widely available, and also fungus, that readily "eat" wood...
So, no surprise.
But if you have an environment with a lot of salts, those that would petrify wood, well, few bacteria and fungus would survive when the high mineralization time, and then, when flood goes down, they should recolonize media an return to eat wood... That takes some time. More than 7 years... Far more....

Kauri wood is also still burnable, in a not too cold climate and is not mineralized.... And as old as you say... So, I have the proof in hand. Thanks.
If wood is in a layer of clay, out of oxygen, out of water, well, fungus and bacteria need so (yes anaerobic bacteria ones, no oxygen), but all need water. No water, no decomposition... So, again no wonder...

But mineralizing needs water, so.....

Then, answer is true but just too general. Wood could be readily decomposed, but to be mineralized needs some conditions that make it. A quickly mineralized wood, as we understand it, or so I think we understand..., a siliceous piece that is pseudo wood, but no more wood (organic mater), well, quickly means several thousands of years. In Earth. Not in a labo...

With best wishes

Lluís

[Vinoterapia]

Hi Pierre.

As you have seen, the examples quoted for a quick "petrification" of wood are rather extreme, associated with active volcanic areas and/or water seeping into mines. Certainly, a source for a mineral-rich water-solution would be needed. Thus, if those conditions would exist in my backyard, I would not like my grandchildren playing in such area, I do not think that would be "healthy".

As some other fellows in the forum, I do not believe Daniel statement of a log being petrified in less than a year. How quick this would happen, well the examples posted mentioned several years under the right (extreme?) conditions.

[Pierre Joubert]

Hi Vinoterapia and lluis. here are 2 extracts that I find interesting. It seems to me quite obvious that the wood in question is from (b)

(a) Artificial petrified wood has been produced in a Washington laboratory. In the process, small cubes of pine are soaked in an acid bath for two days, then in a silica solution for another two. The product is then cooked at 1400 °C in an argon atmosphere for two hours. The result was silicon carbide ceramic which preserved the intricate cell structure of the wood.''

https://en.wikipedia.org/wiki/Petrified_wood

The point is that petrified wood can be made by man in less than a week, simulating nature (the silica method)

(b) 'There are several lakes, rivers and streams in the world which petrify wood, changing it into stone, but none so rapidly as the above Californian stream, so far as we are aware. It must be very strongly charged with the carbonate of lim'.

https://www.scientificamerican.com/article/a-petrifying-stream/
(link normalized by FMF)

[James Catmur]

[lluis]

Hi, Pierre

Thanks for the two links!

The first, I agree with it: impregnated in a silicate, then changed to silica by acid, and then organic matter first burnt to carbon, and this with silica, making silicium carbide, carborundum.
Neat, and true. But just not "petrified wood". Just a complex way to make carborundum in a sophisticated way, preserving shape of previous wood...

Second: not true. Just making epimorphs of anything due to calcium carbonate precipitation.
Again, not "petrified wood", just lime covered wood (that can degrade later...Or not ).

But not silica replacing organic wood...

Say me chemist. Or odd... At the end, the fame we have is as bad as anything you wish to imagine..... :-(

With best wishes

Lluís