Korektor

How did I figure out that natron dissolves granite? With difficulty. First I had to forget what school taught me about stone. Granite isn't some sacred, eternal material. Roughly three quarters of it is SiO₂, quartz. The rest is metal oxides: aluminium, sodium, potassium, calcium, iron. (Just like wood ash. Remember that, it matters later.) A Mohs hardness of 6–7 isn't a verdict, just a physical state. The real question is what breaks down quartz. Glassmakers have known the answer for centuries: molten natron (Na₂CO₃) takes SiO₂ apart at 851 °C. SiO₂ + Na₂CO₃ → Na₂SiO₃ + CO₂ What's created in the reaction is a strong glue, called waterglass. The main ingredient of artificial stone. Oops! I tried dismantling a piece of red granite with charcoal embers, a tin can and washing soda (=natron). The result is in the photo, after removing the dry waterglass with a plastic(!) tooth brush. Later, in my garden, I etched granite with NaOH and KOH separately, at around 360–400 °C. This year, with a NaOH–KOH eutectic mix, 168 °C was enough. That's all it takes for the "invincible" stone. I discovered nothing. Glassmakers, ceramicists and recyclers all know this. Nobody had just connected it to the scoop marks on ancient stones. Let’s connect the dots, archeologists!