- 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
Transcriber’s Notes
- Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
- Corrected a few palpable typos.
- Included a transcription of the text within some images.
- In the text versions only, text in italics is delimited by _underscores_.
- Added a label to one figure (to match the Table of Illustrations).