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). End of Project Gutenberg's Texas Rocks and Minerals, by Roselle M. Girard