P Packsaddle Mountain: [87] Packsaddle Schist: [87] Palangana salt dome: [91], [97] paleontologists: [2] parting of minerals: [17] Pavitte prospect: [53] Pecos County: [9] Pecos River: [65], [74], [75] pegmatite: [41], [55], [56], [58], [76], [77], [79], [81], [94], [95] Baringer Hill: [80] Pennsylvanian: [3], [45], [51], [55], [69], [70], [86], [88] peridotite: [88] period: [2] Permian: [1], [3], [20], [21], [43], [45], [49], [52], [55], [64], [65], [69], [86], [90] Permian basin: [42], [43], [65], [66] [petrified wood]: [20], [52], [78], [84] petrologists: [2] phenocrysts: [85] physiographic outline map: [42] pitchblende: [28], [95], [97] placer deposits: [60] Plata Verde mine: [90] Polk County: [98] porphyritic rocks: [45], [85] portland cement: [51], [69], [88] Precambrian: [2], [3], [44], [45], [48], [52], [53], [56], [58], [59], [60], [61], [63], [67], [72], [74], [75], [76], [79], [82], [85], [87], [93], [94], [95], [97] precious opal: [78] Presidio County: [45], [49], [57], [60], [62], [67], [77], [78], [84], [85], [90], [97] Presidio mine: [60], [90] properties of minerals: [14] pseudomorphs: [70], [87] pulverulent limestone: [41], [69] pumicite: [97], [98] pyramidal cleavage: [74] pyrite: [19], [26], [60], [70], [80], [87] pyrolusite: [27], [73], [74] pyroxene: [45]
Q quartz: [8], [20], [29], [30], [31], [33], [36], [37], [38], [48], [51], [54], [56], [59], [60], [61], [68], [72], [78], [79], [80], [81], [84], [85], [86], [94] agate: [21], [83], [84] amethyst: [37], [82] chalcedony: [16], [21], [45], [78], [81], [83], [86] chert: [19], [40], [81], [84] cryptocrystalline: [81], [84] jasper: [81], [84] milky: [82] onyx: [84] rock crystal: [82] rose: [82], [83] smoky: [82], [83] quartzite: [41], [74], [84], [86] Quaternary: [2], [3], [51], [79], [98] quicksilver (see also [mercury]): [50] Quitman Mountains: [57], [58], [60], [62], [67], [82], [90]
R radioactivity: [95], [96] Real County: [49], [51] Recent: [2], [3] “red beds”: [52] red ocher: [67] reef limestone: [1], [12] Reeves County: [65], [85], [91] reference books: [24], [39], [100] refraction, double: [46] rhombohedral cleavage: [46], [54] rhyolite: [40], [85] porphyry: [41], [85] Rio Grande: [83], [84], [97] rock— crystal: [82] gypsum: [40], [65] identification charts: [39] salt: [40], [65] units: [2] rocks, definition of: [8] Rodda, Peter U.: [vii] rose quartz: [82], [83] rosettes: [63], [64] Rustler Springs area: [91] rutile: [82]
S salt (see also [halite]): [40], [65], [66] domes: [43], [58], [64], [66], [91], [97] lakes: [66] rock: [40], [65] Salt Fork of the Brazos River: [43] sand: [41], [58], [72], [85], [91] blast: [86] building: [85] filtering: [86] glass: [85]-86 sandstone: [41], [52], [55], [58], [59], [72], [76], [81], [84], [86] Sandy Creek: [60] San Saba County: [70], [88] Santa Anna: [86] satin spar: [64] Satorsky, Cyril: [vii] scale, geologic time: [2], [3] scintillation counter: [96] schist: [41], [56], [58], [72], [73], [76], [81], [87], [93] actinolite: [87] graphite: [63], [87] hornblende: [87] mica: [76], [87] talc: [87], [93] schistosity: [87] schorl: [95] Scurry County: [98] sedimentary rocks, definition of: [10] sediments: [8], [11] chemical: [12] selenite gypsum: [63], [64], [76] series: [2] serpentine: [34], [40], [44], [75], [87], [93] serpentinite: [87] Seven Heart Gap: [45] Shafter: [57], [58], [60], [67], [90] Shafter Lake: [83] shale: [12], [13], [19], [40], [45], [70], [87], [88] oil: [88] Shelby, Cader A.: [vii] Sheridan prospect: [53] siderite: [70] Sierra Blanca: [58], [67], [82] silicified wood (see also [petrified wood]): [20] silt: [12], [85] siltstones: [12] silver: [26], [52], [57], [59], [89] glance: [90] horn: [90] minerals: [89] native: [26], [89] Silver Creek: [58] sinter, calcareous: [46] slate: [13] Smith County: [70] smoky quartz: [82], [83] soapstone: [40], [93] soils: [10] Solitario uplift: [42], [88] Sonora: [18] Caverns of: [19] specific gravity: [18], [99] specular hematite: [67] sphalerite: [57] Spiller mine: [74] Spindletop salt dome: [91] Spring Creek: [56] stalactites: [18], [19] stalagmites: [18], [19] Starr County: [84], [98] static metamorphism: [13] Stonewall County: [52] streak or powder of minerals: [17] streak plate: [17], [22] Streeter: [48], [94] striations: [81], [95] strontianite: [49] strontium: [49] sulfur: [29], [30], [31], [32], [34], [36], [81], [90] Sutton County: [18], [19] system: [2]
T talc: [28], [29], [34], [87], [93] schist: [87], [93] Talc Rock: [93] Taylor County: [45], [49], [60] Terlingua area: [46], [47], [49], [50], [65] Tertiary: [2], [3], [9], [21], [45], [49], [51], [52], [56], [57], [60], [70], [77], [78], [79], [83], [84], [85], [86], [90], [97], [98] terrazzo— chips: [55], [76] floors: [88] tests, chemical (see [chemical tests]) thorium: [80] Thrall oil field: [88] time, geologic: [2], [3] tin: [47] topaz: [36], [38], [94] tourmaline: [33], [82], [94] Town Mountain: [95] Trans-Pecos area: [9], [10], [45], [60], [62], [69], [78], [82], [83], [84], [85], [87], [89], [90], [98] trap rock: [45] travertine: [46] Travis County: [20], [45], [46], [49], [68], [69], [70], [88] tremolite: [44], [93] Triassic: [3], [45], [87] Trinity County: [98] tufa, calcareous: [46] twinned crystals: [46], [63] tyuyamunite: [97]
U Upshur County: [70] uranium: [80], [95], [96] minerals: [95] uraninite: [97] uranophane: [31], [95], [97] Uvalde County: [45], [60], [84], [88]
V Valley Spring Gneiss: [59] Val Verde County: [45], [74], [75] Van Horn area: [42], [52], [53], [58], [59], [60], [75], [76], [79], [85], [87], [90] Van Horn Mountains: [45], [55], [76], [79], [95] Van Zandt County: [66] verde antique: [88] vesicles: [45] vitrophyre: [40], [77] volcanic ash: [41], [97] volcanic igneous rocks, definition of: [9] volcanoes: [9], [97], [98]
W Waco: [88] wad: [73], [74] Walker County: [52] Ward County: [66] Washington County: [78], [84] weathering: [11] Webb County: [11], [84] Weches strata: [70] Wharton County: [91] white mica (see [muscovite]) Wilbarger County: [98] Willacy County: [66] Williamson County: [20], [60], [69], [70], [88] Willow City: [94] wood opal: [78] wood, petrified: [20], [52], [78], [84] Wylie Mountains: [95]
Y yellow copper ore: [53] Yoakum County: [66] Young County: [58] yttrium: [80]
Z Zapata County: [83], [84] Zavala County: [86] zirconium: [80]