Homemade petrified wood?

[Mark Nelson]

I know some people have used petrified wood for handles so this might be of interest.I wonder if it would work for horn and such? If someone had a argon oven I guess they could do this at home. Neat idea anyway.

http://www.pnl.gov/news/2005/05-03.htm

 

[F. Allin Kahrl]

Argon oven? Knifemakers use stainless foil. If someone (YO! FITZO!) can tell me what kind of acid to use and how to make a "silicon solution" I'll try it in the furnace at work.

 

[fitzo]

That's 1400 CENTIGRADE. That's 2500 Farhenheit. Pretty warm. Exposure with any oxygen around will succeed in re-inventing the manufacture of charcoal.

Silica is soluble in acid. (Silica is silicon dioxide, like the little moisture-sucker packets that come packaged with electronics to protect them.) Glacial acetic acid will work. It's also combustible, so that's probably not a good idea without the inert gas. Silica is also soluble at very high pH, so sodium hydroxide will also dissolve it.

However, I don't think this process is exactly what the article makes it sound like. "Petrified wood" this is not. Once again we have a science writer attempting to reduce a topic to colloquial terms, and misleading people as a result. This is the transformation of the cellular matrix of wood into silicon carbide using the cellulose of the wood as the carbon source to carburize the silica. It is going to end up black and plain and look like a fine grit bench-grinder stone or wet-or-dry sandpaper.

Hopefully "shgeo" Steve will step in and clarify here, as petrified wood is made by infiltration of quartz and other minerals and is totally unlike what this process is really describing.

 

[mete]

Allin you've confused silica with silicone. Silicone is a compound containing silicon and is found in the many silicone oils, waxes, greases,sealers etc , on the market. Silica is silicon dioxide or sand ! Speaking of fossils , does anyone know about the Cardiff Giant ?

 

[Mike Hull]

Why not just have your wood, and horn stabilized?? You can do that now.

Edited to add; IIRC, the cardiff giant was a hoax.

 

[F. Allin Kahrl]

That's 1400 CENTIGRADE. That's 2500 Farhenheit. Pretty warm. Exposure with any oxygen around will succeed in re-inventing the manufacture of charcoal.

Woops! I missed that bit. Our furnace only goes to 2250ºF (theoretically) and we never run it that hot. Oh well.

However, I don't think this process is exactly what the article makes it sound like. "Petrified wood" this is not. Once again we have a science writer attempting to reduce a topic to colloquial terms, and misleading people as a result.

Yeah, I realize that true petrified wood is the result of the same sort of mineral leaching that creates formations like stalactites and stalagmites. Still, I was thinking that a matrix permeated with S/C would make a pretty incredible, long-wearing handle material, and might look cool, too. The chemicals involved are more than I bargained for, though.

Allin you've confused silica with silicone. Silicone is a compound containing silicon and is found in the many silicone oils, waxes, greases,sealers etc , on the market. Silica is silicon dioxide or sand !

Thanks for the correction mete; I mis-spoke. I did mean silicon, not silicone, like they make integrated circuits from. Sorry, bad habit, grew up in the '80s when everyone was talking about "silicon chips" in computers. I still seem to have trouble remembering that silica is a compound of silicon, not the same thing.

Well, scratch that.

-Allin

 

[Steve Hayden]

Real petrified wood has the cellular voids and any decomposing areas of cellulose replaced by minerals that seep in dissolved in groundwater. The better grades are composed of microcrystalline quartz, stained by metal-oxides. Quartz (SiO2) is only slightly soluble at normal temperatures in weakly acidic solutions like groundwater. Quartz is more soluble in HF, but the organics would go away. Calcite (CaCO3) is more soluble, but makes inferior petrified wood. Highly mineralized waters, like in hot springs may react with wood fibers and made a low grade petrified product in just a few years, but the really nice stuff is much older, in the millions of years.

No natural petrified wood is made from SiC. Organic compounds form graphite and volatiles above 400°C, that is they will form a black film and gasses that escape in fluids. To form SiC, you have to have a reducing environment at much higher temperatures than petrified wood ever gets to, hence the Ar furnace.

What they made is a ceramic.

 

[Stacy E. Apelt - Bladesmith]

Even if you survived making this at home (which is not a guarantee) you would have to have diamond grinders to shape it.Also you would only have a 1/2" cube of material to work from. For those who have lapidary equipment,real petrified wood,bone,and ivory are readily available - and much prettier.