Part 10

Plate IV

Plate V

Plate VI

Index

A actinolite: 26 agate: 20, 28, 38 agatized wood: 27 allanite: 21 almandite: 22 amazonite: 23 amazon stone: 23 amber: 18 amethyst: 25 Amethyst Hill: 25 amorphous gemstones: 9 andalusite: 30 Arkansas: 19 Armstrong County: 21 augite: 18, 28

B Baringer Hill, Llano County: 21, 26 baroque pearls and/or stones: 17, 25 bediasite (tektite): 28-29, 39 beryl: 18 Big Bend National Park: 27 biotite: 23 Blanco County: 18, 22 Brazos County: 29 Brazos River: 25 Brewster County: 18, 23, 24, 25, 26, 27, 28, 31, 36 brilliancy: 5 brilliant cut, standard American: 13, 15, 16 Brown County: 19 Burleson County: 29 Burnet County: 20, 22, 23, 25, 26, 30, 37

C cabochon gems: 10-12 Caddo Lake: 25 carbuncle: 22 carnelian: 27 cassiterite: 23, 29 celestite: 19, 35 chalcedony: 27 geodes: 26 chuck: 15, 17 citrine: 25-26 cleavage: 6, 13 coal: 22 Coke County: 19 color: 5 Colorado River: 25 Concho River: 25 crown girdle facets: 16, 17 crown of gemstone: 15, 16 crystals: 7-9 crystal systems: 7 crytolite: 21 Culberson County: 22, 23, 25, 26, 31 culet: 13 cutting and polishing: 10-17 cutting lap: 13

D DeWitt County: 29 diamond: 19 saw: 10, 11 diaphaneity: 5 dispersion: 6 dopping: 12, 13 dop-stick: 12, 15, 17 dop-wax: 12, 15, 17 dravite: 30 durability: 6 Duval County: 21, 24

E El Paso County: 22, 30, 31 emerald cut: 15 epidote: 19-20

F facet, kinds of: 13 main: 16 skill: 16 table: 13, 14 faceted gems and/or stones: 10, 13-17 Fayette County: 20, 29 fergusonite: 21 fire: 5 Fisher County: 19 fluorite: 20, 21 Foard County: 19 fossil wood: 20-21, 22 fracture: 6 Franklin Mountains: 18

G gadolinite: 21-22 garnet: 20, 22, 36 gemstones, by kinds: 18-31 geodes, celestite: 19 Georgia: 29 Gillespie County: 18, 22, 23, 25, 26, 30, 36 girdle facets: 16 gneiss: 22 Gonzales County: 20, 29 grain: 25 gram: 7 graphite: 30 Grimes County: 29 grinding: 12 Guadalupe River: 25 Gulf Coast: 25 Gulf Coastal Plain: 18, 20, 22, 35

H hardness: 6 Hudspeth County: 18, 20, 22, 24, 25, 26, 27, 28, 31

I index of refraction: 5

J jasper: 27-28 Jeff Davis County: 26, 27, 28, 31 jet: 22

K Kinney County: 28

L labradorite: 23, 36 Lake Buchanan: 21 Lampasas County: 19 lap plate: 13 Lavaca County: 29 Lee County: 20, 29 lignite: 22 Live Oak County: 21 Llano County: 18, 19, 20, 21, 22, 23, 25, 26, 30, 31, 40 Llano River: 25 luster: 5

M Madeira topaz: 29 Mason County: 20, 22, 23, 26, 29, 30, 39, 40 Massachusetts: 29 Maverick County: 18 microcline: 20, 21, 23-24, 29, 37 Mohs scale of hardness: 6 moonstone: 28 Mount Bonnell: 19 muscovite: 23

N natural glass: 18, 24, 28 Needle Peak, Presidio County: 27 nivenite: 21 Nolan County: 19 Nueces River: 25

O obsidian: 24, 29 Oklahoma: 29 opal: 20, 24 opalized wood: 35 orbicular jasper: 28 ounce: 7

P Packsaddle Mountain: 23 Packsaddle schist: 30 palm wood: 21, 35 Palo Duro Canyon: 21 pavilion: 13, 16 facets: 16 girdle facets: 16, 17 pearl: 24-25 pegmatites and/or pegmatite dikes: 18, 20, 21, 22, 23, 26, 29, 39 petrified wood: 26 phantom crystals: 26 pistacite: 20 pleochroism: 5 point: 7 polishing: 17 lap: 13, 16 preformed stone: 16 preforming: 15 Presidio County: 20, 22, 24, 25, 26, 27, 28 properties of gemstones: 5-7

Q quartz: 20, 21, 23, 25-28, 29, 30 smoky: 38

R radioactive elements: 22 radioactivity of gadolinite: 21 rarity: 6 Reeves County: 26, 27 Rio Grande: 25 gravels of: 21, 27, 38 Valley: 27 rock crystal: 26 rose quartz: 26

S Sabine River: 25 sanding: 12 sanidine: 28 sawing: 10 scheelite: 20 schorl: 30 size: 7 “skill” facets: 16 “slab” of gem materials: 11 Smithsonian Institution: 21 smoky quartz: 23, 26, 37 smoky topaz: 29 Spanish topaz: 29 specific gravity: 7 spinel: 18, 28 star facets: 17 step cut: 15 streak: 6 synthetic gems: 7

T table facet: 13, 15 tektite (bediasite): 28-29, 39 tenacity: 6 thorogummite: 21 topaz: 23, 26, 29-30, 39, 40 quartz: 29 tourmaline: 26, 29, 30-31, 40 Town Mountain, Llano County: 26, 30 transparency: 6 Travis County: 19, 35 Trinity River: 25 tumbled gems: 17 turquoise: 31

U U. S. National Museum: 30

V value of gemstones: 6, 7 Val Verde County: 24 valverdites: 24 Van Horn, Hudspeth County: 27

W Walker County: 29 Washington County: 20 Webb County: 21 weight, units of: 7, 25

Z Zapata County: 38