J Jackson strata: 97 jasper: 81, 84 Jasper County: 52 Jeff Davis County: 45, 51, 74, 78, 85 Jefferson County: 91 Johnson County: 69 K kaolin: 51 kaolinite: 51 karats: 60 Karnes County: 97, 98 Katemcy: 94 Kendall County: 18 Kenedy County: 66 Kent County: 98 kidney ore: 67 King, Elbert A., Jr.: vii King County: 52 Kinney County: 45 Kleberg County: 66 Knox County: 52 L labeling rock and mineral specimens: 23 labradorite: 45 Lake Buchanan: 80, 83 Lamb County: 79 Lampasas County: 20, 48, 49, 88 lava: 9 lead: 57, 90 Leakey: 51 Lee County: 64, 84 lens: 22 Liberty County: 91 lime: 69 limestone: 12, 13, 18, 19, 40, 43, 45, 46, 49, 54, 55, 56, 57, 58, 60,68, 74, 75, 76, 84, 88, 90, 91 chalk: 69 dolomitic: 68 lithographic: 69 öolitic: 69 pulverulent: 41, 69 limonite: 19, 27, 28, 30, 32, 70, 75, 81, 86 lithographic limestone: 69 Live Oak County: 45, 97 llanite: 41, 71, 81 Llano: 60, 63, 72, 73, 95 Llano County: 44, 45, 55, 56, 58, 59, 60, 61, 63, 70, 71, 72, 73, 76, 78, 80, 83, 87, 88, 94, 95 Llano uplift: 10, 18, 42, 44, 52, 55, 56, 58, 59, 60, 61, 62, 63, 67, 70, 72, 76, 77, 79, 80, 82, 83, 84, 85, 86, 87, 88, 93, 94, 95 Lone Grove: 63 Lone Star: 70 Longhorn Cavern: 18 Long Point salt dome: 91 Lonsdale, John T.: vii luster of minerals: 16 Lytton Springs oil field: 88 M Macon, James W.: vii magma: 9 magnesium, source of: 55 magnetite: 28, 67, 70, 72, 85, 87, 93 malachite: 34, 52, 53, 54 Malone Mountains: 65 manganese: 73, 75 map— geologic: 4-5 physiographic outline: 42 Marathon area: 42, 84, 88 marble: 13, 14, 40, 46, 54, 75 Marble Falls: 62 Marion County: 70 martite: 67 Mason: 74 Mason County: 48, 55, 58, 59, 60, 61, 67, 72, 73, 74, 76, 80, 83, 94 masses, crystalline, definition of: 14 Matagorda County: 91 Mayfield prospect: 74 McCulloch County: 88 Medina County: 45 Menard County: 65 mercury: 8, 49, 50, 51 metamorphic rocks, definition of: 12 metamorphism, definition of: 13, 14 mica (_see also_ biotite; muscovite): 8, 60, 61, 63, 64, 72, 76, 79, 80, 85, 87 mica gneiss and/or schist: 59, 76, 87 Mica Mine area: 58, 76, 77, 79 microcline: 55, 56, 61 milky quartz: 82 Mills County: 49 mineral identification charts: 24 mineralogists: 2 minerals, definition of: 7, 14, 15 Mississippian: 3, 55, 69, 88 Mitchell County: 66 Mohs scale of hardness: 16, 17 molybdenite: 63 montmorillonite: 51 Morris County: 70 moss agate: 84 Moss Bluff salt dome: 91 muriatic acid: 22 muscovite: 31, 32, 34, 37, 38, 76