Part 30

F Fairland: 54 Falfurrias: 64 Fannett salt dome: 91 Fayette County: 52, 64, 84, 98 feldspar: 8, 29, 30, 31, 33, 34, 35, 37, 45, 51, 55, 59, 61, 72, 79, 80, 85, 86 albite: 55 amazonstone: 56 microline: 55, 56, 61 orthoclase: 55, 61 fibrous gypsum: 64, 65 filtering sand: 86 Fisher County: 20, 49, 58, 65 Flawn, Peter T.: vii flint: 84 flowstone: 18 flow structure: 85 fluorite: 29, 32, 34, 35, 37, 38, 56, 72 Foard County: 52, 58 foliation: 87 fool’s gold: 53, 80 formation: 6 Fort Bend County: 91 Fort Worth: 88 fracture of minerals: 17 fragmental rocks: 12 Franklin Mountains: 48, 58, 62, 85 Frasch method of sulfur mining: 91, 92 Fredonia: 67 Freer: 78, 83 furnace (see blast furnace; open-hearth furnace)

G gabbro: 87 gneiss: 59 Gaines County: 83 galena: 17, 26, 57, 89, 90 argentiferous: 57, 90 Galveston County: 91 Gamble prospect: 67 gamma rays: 96 garnet: 31, 33, 34, 37, 58, 85, 87 Garza County: 97 Geiger counter: 96 gemstones: 56, 58, 77, 82, 94, 95 geode: 19, 46, 49, 82 geologic map: 4, 5 geologic time scale: 2, 3 geologists: 2 geology: 2 Gillespie County: 44, 45, 55, 58, 59, 60, 61, 65, 76, 80, 82, 83, 87, 88, 94 glass, natural: 9, 77, 85, 97 glass sand: 85-86 glauconite: 70, 73 glossary: 102-103 gneiss: 13, 41, 55, 56, 59, 67, 72, 73, 74, 76, 81, 87, 93, 97 conglomerate: 59 gabbro: 59 granite: 59 hornblende: 59 mica: 59 goethite: 70 gold: 26, 51, 59, 80, 90 fool’s: 53, 80 Gonzales County: 52, 84, 97 Grand Saline salt dome: 66 granite: 2, 8, 9, 13, 41, 48, 55, 56, 59, 61, 72, 76, 79, 81, 85, 87, 94, 95 gneiss: 59 opaline: 72 Granite Mountain: 62 Granite Shoals Lake: 56 granules: 85 graphite: 26, 27, 62, 75 schist: 63, 87 gravel: 12, 41, 91 green copper carbonate: 53 greensands: 70 Grit: 94 grossularite: 58 group: 6 Guadalupe Mountains, Peak: 1 Gulf Coast: 91 Gulf Coastal Plain: 20, 42, 43, 46, 51, 52, 58, 60, 65, 66, 78, 83, 84, 86, 87, 92, 97, 98 Gulf salt dome: 91 Gyp Hill salt dome: 64 gypsite: 65 gypsum: 28, 29, 30, 32, 36, 37, 43, 63, 70, 85, 91 alabaster: 65 fibrous gypsum: 64, 65 rock gypsum: 40, 65 rosettes: 63, 64 satin spar: 64 selenite: 63, 64, 76

H halite: 28, 32, 34, 35, 36, 38, 40, 43, 65, 91 hand lens: 22 Hardeman County: 52, 58, 64, 65 hardness of minerals: 16, 99 Harris, Bill M.: vii Harris, John S.: vii Harris County: 65, 66 Hartley County: 79 Hays County: 45 Hazel Formation: 52 Hazel mine: 52, 53, 90 Heath mine: 60 hematite: 26, 27, 36, 66, 75, 84, 86 specular: 67 Henderson County: 70 High Island salt dome: 91 High Plains: 42, 46, 51, 65, 66, 78, 79, 83, 87, 97, 98 Hockley salt dome: 65, 66 hollandite: 26, 27, 28, 73, 74 Honey Creek area: 87 hornblende: 8, 59, 61 gneiss: 59 schist: 87 horn silver: 90 Hoskins Mound salt dome: 91 Houston: 70 Howard County: 45, 60 Hudspeth County: 45, 52, 53, 55, 56, 57, 58, 59, 60, 62, 65, 66, 67, 75, 79, 82, 83, 90, 93, 95 Humphreys, Alan: vii Hutchinson County: 66 hyalite: 78 hydrochloric acid (see also chemical tests): 18, 22

I identification charts: 24 igneous rocks, definition of: 9 intrusive igneous rocks, definition of: 9 Irion County: 60 iron: 59, 66, 67, 69, 70, 72, 73 Iron Mountain: 73

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

N Nacogdoches County: 70 Nash salt dome: 91 native elements: 8 native mercury: 8 native silver: 26, 89 nodule: 19, 44, 49 Nolan County: 20, 49, 63, 64, 65 north-central Texas: 43, 51, 52, 69, 70, 86, 88

O Oakville strata: 97 obsidian: 40, 77 occurrence of minerals: 14 ocher, red: 67 octahedral cleavage: 56, 57 oil shale: 88 olivine: 88 onyx: 84 öolitic limestone: 69 opal: 21, 29, 30, 31, 35, 37, 38, 78, 86 opaline granite: 72 opalized wood: 20, 78, 84 open-hearth furnace: 70, 72 Orchard salt dome: 91 Ordovician: 3, 55, 69, 84 orthoclase: 55, 61

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

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).