#mining #nickel, #manganese, and #cobalt from #olivine (as well as iron and magnesium, of course) at Aspiring Minerals
on 02025-07-27Glauber, the dude who discovered Glauber’s Salt, precipitated #potassium-silicate using ferrous chloride — in 1646! I guess the “chemical garden” he produced was made of fayalite #olivine — or does fayalite have a softer hydrated version, like talc? (Apparently serpintinization turns fayalite into magnetite, silica, and hydrogen, so probably not.)
on 02015-08-30The weathering reactions of an #olivine like #forsterite and fayalite into serpentine in the presence of water, and also pyroxenes like #enstatite into talc and magnesian chlorite. Serpentine’s Mg:Si ratio is 3:2, in between forsterite’s 2:1 and enstatite’s 1:1.
on 02015-08-30“Lime #olivine” (which I guess is a calcium analogue of forsterite) “does not hydrate, and is avoided in #cement manufacture”, but apparently heating it above 500° “cures” that “problem”. Also called #larnite. Also, this page explains that forsterite weathers to serpentine and brucite in nature.
on 02015-08-30No, wait, "forsterite" (an #olivine; Mohs hardness 7! Gemstone peridot!) is magnesium silicate, Mg₂SiO₄. I thought that was talc? Apparently talc is hydrated, so I’m guessing that precipitating #waterglass with magnesium is going to give you something more like talc than like forsterite, which also has a 2:1 Mg:Si ratio, compared to talc’s 3:4 Mg:Si ratio; so baking out the water probably wouldn’t be enough. #Refractory #materials: doesn’t melt until 1900°! (And iron ions, but only iron(II) ions, can replace the magnesium in any concentration.) But wait! There’s #enstatite! #materials #minerals
on 02015-08-30"Olivine" is magnesium iron silicate, which is I guess what you get if you precipitate #waterglass with magnesium and iron salts? Or will the hydration interfere with that and give you a softer and weaker material, like talc? #minerals
on 02015-08-30