- Modality
- NIR
- Category
- mineral
- Material Type
- Tectosilicate
- Sample ID
- GDS31 0-74um fr
- Collection Locality
- Brazil
- Spectral Purity
- 1a2_3_4_ # GDS31 0-74um fr # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
- Composition / XRD
- None # XRF, EPMA, ICP(Trace), WChem COMPOSITION_TRACE:
- Sample Description
- Polymorphous with Tridymite, Cristobalite, Coesite and Stishovite. Quartz (Si02) is an important constituent of igneous rocks which have an excess of silica, such as granite, rhyolite or pegmatite. Because it is extremely resistant to both mechanical and chemical attack, it usually survives the weathering process. Quartz is an extremely difficult mineral to grind without contamination, because of its hardness. "Results of petrographic examination: Hand sample appears entirely pure, being a clear and transparent fragment of a single crystal. Under petrographic microscope, sample also pure and clear." Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263. IMAGE_OF_SAMPLE: NO PHOTO
- XRD Analysis
- Pure quartz. (Jack Salisbury) Pure quartz. (Norma Vergo)
- X Units
- cm⁻¹
- Y Units
- Absorbance
- Data Points
- 2,126