Making silicon industrially requires extreme and expensive conditions. Silica is melted in a furnace at around 1,700 ºC and is reacted with carbon to produce impure silicon. But, Nohira and his colleagues at Kyoto University in Japan; could convert silica to silicon without melting. They immerse a piece of silica - a quartz plate, say - in a bath of molten calcium chloride salt at 850 ºC, and pass an electric current through a metal wire touching the quartz. Where metal touches silica, the oxygen atoms in the silica become oxide ions, which dissolve in the molten salt - and the silica turns slowly into silicon.
Like with most metals, you can reduce silicon oxide with aluminum in a termite-like reaction:
3 SiO2(s) + 4 Al(s) -> 3 Si(l) + 2 Al2O3(l)
Powdered quartz and aluminum are mixed, filled into a ceramic pot (e.g., flower pot) and ignited (with an ignition cherry). Be warned though: The reaction is extremely exothermic (Delta G ~ -800 kJ/mol). The mixture gets over 2500 °C hot and sends drops of molten metal several meters away. Be sure nothing flammable is nearby, including yourself! The reagents have to be completely dry, otherwise hydrogen gas would develop, the resulting explosion would send molten material around. Once ignited, the reaction cannot be extinguished until the reactants are used up. Do not use metal containers, as they would melt. Wait until the mixture has completely cooled out before you examine it! You should easily see the dark grey, shiny, crystalline pieces of silicon.