Gem-quality beryl has not been reported in Texas. A discussion of beryl is included herein because the writer believes it likely that beryl of gem quality will be found in Texas as a result of future investigations and exploration. Beryl crystals have been found in pegmatite dikes in Llano, Blanco, and Gillespie counties. These crystals are commonly several inches long and exceed 1 inch in diameter but are very badly fractured. Most of the beryl crystals do not approach gem quality and are entirely unsuitable for any lapidary use. The color of the crystals found thus far is bluish, greenish, pinkish brown, yellowish, and colorless. Some very tiny colorless beryl crystals have been found that are transparent, but thus far such crystals have been too small to be cut into gems. Fine blue beryl crystals have been found in the Franklin Mountains near El Paso, Texas. Unfortunately, these crystals are so badly flawed and fractured that they are not suitable for lapidary use. It seems likely that careful prospecting of Texas pegmatites will reveal at least some gem-quality beryl. Celestite _Composition_: SrSO₄. _Crystal system_: orthorhombic. _Hardness_: 3.0 to 3.5. _Specific gravity_: 3.95 to 3.98. _Luster_: vitreous. _Color_: white, blue, greenish, reddish, and brownish. _Streak_: white. _Cleavage_: three directions, although one of these directions is not easily developed. _Fracture_: uneven. _Tenacity_: brittle. _Diaphaneity_: transparent to subtranslucent. _Refractive index_: 1.62 to 1.63. _Dispersion_: moderate. Celestite is very seldom cut into gems. Being very soft, brittle, and having three cleavages, celestite is completely unsuitable for jewelry. These same properties make this mineral exceedingly difficult to facet; however, faceted stones are seen in large collections. [Illustration: Fig. 14. Common crystal form of Travis County celestite. Same crystal form as shown in Plate I, A.] Fine crystals of colorless and blue gem-quality celestite (Pl. I, A, and fig. 14) have been found at Mount Bonnell and other localities west of Austin, Travis County. The celestite crystals occur in vugs or geodes in limestone. The crystals are mostly white or colorless and fractured near the base or where attached, but the tips of the crystals are commonly clear celestine blue and completely free of flaws. Crystals several inches in length have been found, but the average size is about 1 inch. The smaller crystals are frequently more transparent and consequently better suited for cutting. It is very difficult to obtain crystals that will allow the cutting of flawless stones of more than 4 or 5 carats. Bluish and colorless celestite of gem quality and fine crystals have been found near Lampasas, Lampasas County, and near Brownwood, Brown County, but neither of these localities has been very productive of good gem material.