Scapolite, typically found where impure limestones have been crystallized by contact with an igneous magma Location: Listed as 10 miles northwest of Burnet County: Burnet County, Texas Chemical Formula: end member Na4Al3Si9O24Cl to end member Ca4Al6Si6O24CO3 Crystal System: Tetragonal Specimen size: 4 x 2.5 x 3 inches Specimen weight: 523 grams In the Jackson School Collection, at the University of Texas at Austin.
Scheelite in limestone with garnets, hematite, calcite, epidote Location: not listed, but assume to be in the Quitman Mountains associated with an often noted skarn (intrusive contact with host limestone). Chemical formula: Ca(WO4) Crystal system: Tetragonal Left Specimen size: 7 x 5.5 x 3.5 centimeters Right Specimen size: 12 x 4.5 x 5 cm Left Specimen weight: 237 grams Right Specimen weight: 521 grams Collection reference: TMM 701 Additional Information: "The tungsten-bearing mineral scheelite has been known since 1916 in recrystallized sugary limestone beds of the Torcer Formation where it has been metamorphosed on the west side of the Quitman pluton and west of a line projected along the Bonanza fissure (Udden, 1941). According to a report by J. F. McAllister (written commun., 1942), the scheelite is in isolated grains, coarse aggregates, and thin veinlets replacing the limestone. Kock discontinuously mineralized with tungsten was traced for about 700 feet along the contact zone. The principal minerals associated with the scheelite are specular hematite, garnet, epidote, tremolite, pyrite, quartz, calcite, and secondary copper minerals." (from "Geology of the Sierra Blanca Area, Hudspeth County, Texas" Albritton & Smith, USGS Professional Paper 479, 1965.)
Characteristic Fluorescence (short wave) of Scheelite in limestone with garnets, hematite, calcite, epidote Location: not specifically listed, but assume to be in the Quitman Mountains associated with an often noted skarn (intrusive contact with host limestone). Chemical formula: Ca(WO4) Crystal system: Tetragonal Left Specimen size: 7 x 5.5 x 3.5 centimeters Right Specimen size: 12 x 4.5 x 5 cm Left Specimen weight: 237 grams Right Specimen weight: 521 grams Collection reference: TMM 701 Additional Information: "The tungsten-bearing mineral scheelite has been known since 1916 in recrystallized sugary limestone beds of the Torcer Formation where it has been metamorphosed on the west side of the Quitman pluton and west of a line projected along the Bonanza fissure (Udden, 1941). According to a report by J. F. McAllister (written commun., 1942), the scheelite is in isolated grains, coarse aggregates, and thin veinlets replacing the limestone. Kock discontinuously mineralized with tungsten was traced for about 700 feet along the contact zone. The principal minerals associated with the scheelite are specular hematite, garnet, epidote, tremolite, pyrite, quartz, calcite, and secondary copper minerals." (from "Geology of the Sierra Blanca Area, Hudspeth County, Texas" Albritton & Smith, USGS Professional Paper 479, 1965.)
