| graphs gems gemstone's physical chemistry, occurrence, properties, and market potential. And spectacular...MATERIALS 16 16 239 / 18 / 19 / Luminescence Occurrence / Stone Sizes 233 15 / Comments / Journals...cases the text lists only the pervasive rences, mining and cutting techniques, or market and or especially...brilliance derived from the cutting. At the same time, hot spots or specular reflections from individual facets...soften gradually and eventually begin to flow. Obsidian and tektites are examples of naturally occurring |
|
|
 |
MacDonald, Ray, Smith, Robert L., Thomas, John E. (1992) Chemistry of the subalkalic silicic obsidians. Professional Paper 1523. US Geological Survey doi:10.3133/pp1523 |
Report (issue) |
| 1C402,12201 Sunrise Valley Dr. SALT LAKE CITY, _Utah_-Federal Bldg., Rm. 8105,125 South State St. SAN...references (p. ) Supt. of Docs, no.: I 19.16:1523 1. Obsidian Composition. I. Smith, Robert L. II. Thomas, John...Or-Ab-An-H2O plots Notes on the occurrence, geology, and petrography of the obsidian subgroups Group I: Obsidians...47 48 50 51 Application to the whole body of obsidian data Magma mixing and assimilation Vapor-phase...discrimination plots Geochemical features of main obsidian groups Group I: Obsidians from primitive island |
|
|
