珪藻[keisou] diatom
珪藻土[keisoudo] diatomaceous soil
二酸化珪素[nisankakeiso] silicon dioxide (SiO2)
珪素[keiso] silicon (Si)
珪酸[keisan] silicic acid

珪砂[keisha] silica sand
珪石[keiseki] silica
珪性肺塵症[keiseihaijinshou] pneumonoultramicroscopicsilicovolcanoconiosis
珪素鋼[keisokou] silicon steel
珪素樹脂[keisojushi] silicone resin

サハラ砂漠[saharasabaku] Sahara Desert
黄砂[kousa] loess
角砂糖[kakuzatou] cube sugar
玉砂利[tamajari] gravel
黒砂糖[kurozatou] brown sugar

砂子[isago] sand
砂岩[sagan] sandstone
砂丘[sakyuu] sand dune
砂金[sakin] gold dust
砂時計[sunadokei] hourglass

硅素[keiso] silicon (Si)
硅砂[keisha] silica sand
硅石[keiseki] silica

硅肺[keihai] silicosis
硅酸塩[keisanen] silicate