Bài giảng khoa học đất (ngành quản lý đất đai) chương 2 (2) phần rắn khoáng

Si-oxide • thạch anh (SiO2): màu sắc đa dạng: tím, hồng, vàng,… Fe-oxide/hydroxide • Goethite (FeO(OH)) Yellowish to reddish to dark brown Fe-oxide/hydroxide • Hematite (Fe2O3) Fe-oxide/hydroxide • Limonite FeO(OH)·nH2O Al-oxide/hydroxide • Gibbsite Al(OH)3 Al-oxide/hydroxide • Boehmite (γ-AlO(OH)) White, pale greyish brown; yellowish or reddish when impure; colorless in thin section Al-oxide/hydroxide • Diaspore White, pale gray, colorless, greenish gray, brown, pale yellow, pink, lilac; may exhibit color change Nesosilicate • olivine (lãm thạch) (Mg,Fe)2SiO4 Yellow to yellow-green Nesosilicate • Garnet X3Y2(SiO4)3 The X site is usually occupied by divalent cations (Ca2+, Mg2+, Fe2+) and the Y site by trivalent cations (Al3+, Fe3+, Cr3+) in an octahedral/tetrahedral framework with [SiO4]4− occupying the tetrahedra virtually all colors Nesosilicate • tourmaline is a crystal boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium Most commonly black, but can range from brown, violet, green, pink, or in a dual-colored pink and green Nesosilicate • Zircon Tên hóa học zirconi silicat, cơng thức hóa học ZrSiO4 Cơng thức thực nghiệm vài thay zircon (Zr1-y, Nguyên tố hiếmy)(SiO4)1-x(OH)4x-y Reddish brown, C yellow, green, o blue, gray, l colorless; in o thin section, r colorless to pale brown Inosilicate • Augite is a single chain inosilicate mineral, (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 Dark green to black Inosilicate • Hornblende (Ca,Na)2–3(Mg,Fe,Al)5(Al,Si)8O22(OH,F)2 black/dark green Ca2(Mg, Fe, Al)5 (Al, Si)8O22(OH)2 Phyllocilicate • Talc H2Mg3(SiO3)4 or Mg3Si4O10(OH)2 Mg3Si4O10(OH)2 Color white, grey, green, blue, or silver Phyllocilicate • Biotite (mica đen) K(Mg,Fe)3AlSi3O10(F,OH)2 Dark brown, greenish brown, blackish brown, yellow, white Phyllocilicate • Muscovite (mica trắng) KAl2(AlSi3O10)(F,OH)2, or (KF)2(Al2O3)3(SiO2)6(H2O) White, grey, silvery Phyllocilicate • Illite (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] CEC khoảng 20 – 30 meq/100 g Grey-white to silvery-white, greenish-gray Phyllocilicate • Kaolinite Al2Si2O5(OH)4 White, sometimes red, blue or brown tints from impurities Phyllocilicate • Montmorillonite (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O White, pale pink, blue, yellow, red, green Phyllocilicate • Vermiculite (MgFe,Al)3(Al,Si)4O10(OH)2·4H2O CEC = 100-150 meq/100 g Colorless, white, yellow, green, brown Tectosilicate • Albite NaAlSi3O8 White to gray, bluish, greenish, reddish; may be chatoyant Tectosilicate • Anorthite CaAl2Si2O8 White, grayish, reddish Tectosilicate • Orthoclase KAlSi3O8 Colorless, Greenish, Grayish yellow, White, Pink Sulfate • Gypsum CaSO4·2H2O Colorless to white; with impurities may be yellow, tan, blue, pink, brown, reddish brown or gray halide The halide anions are fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−) and astatide (At−) • Halite (NaCl) • sylvite (KCl) Colorless, Grey, White • Carnallite KMgCl3·6(H2O) (Blue, colorless, yellow, white, red)