DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS180.1B, HS180.2B, HS180.3B, HS180.4B, HS180.6
MINERAL_TYPE: Cyclosilicate
MINERAL: Beryl
FORMULA: Be3Al2Si6O18
FORMULA_HTML: Be3Al2Si6O18
COLLECTION_LOCALITY: Maine
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Theoretical percentages of the oxides in the formula are BeO 14.0%, Al2O3 19.0%, SiO2 67.0%. The presence of alkalis (Na and K) and Li may considerably reduce the percentage of BeO. Small and variable amounts of zeolithic H2O are present.
Sieve interval 74-250µm.
"Results of petrographic examination: Hand sample is pale green and appears pure. Microscopic examination shows that there is a small amount (2% or less) of very fine, low birefringent material in the sample. The grains occasionally have rhombic or cubic shape. These grains are unidentifiable."
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.
Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.2B = <74 µm
.3B = 74-250 µm
.4B = 250-1200 µm
.6 = cut slab
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Pure (Norma Vergo).
Pure beryl.
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.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: # XRF, EPMA, ICP(Trace), WChem
COMPOSITION KEYWORD |
Oxide ASCII |
Amount | Weight Percent, % |
Oxide html |
---|---|---|---|---|
COMPOSITION: | SiO2 | 66.12 | wt% | SiO2 |
COMPOSITION: | TiO2 | 0.01 | wt% | TiO2 |
COMPOSITION: | Al2O3 | 17.36 | wt% | Al2O3 |
COMPOSITION: | FeO | 0.48 | wt% | FeO |
COMPOSITION: | MnO | 0.00 | wt% | MnO |
COMPOSITION: | MgO | 0.17 | wt% | MgO |
COMPOSITION: | CaO | 0.01 | wt% | CaO |
COMPOSITION: | Na2O | 0.35 | wt% | Na2O |
COMPOSITION: | K2O | 0.03 | wt% | K2O |
COMPOSITION: | Total | 84.53 | wt% | |
COMPOSITION: | O=Cl,F,S | wt% | ||
COMPOSITION: | New Total | wt% |
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
"Microprobe analysis shows that grains selected are homogeneous within and between grains. Average of 10 analyses lacking beryllium indicates silica and alumina content appropriate for beryl."
NOTE: EM composition total is the total without beryllium.
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.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
avg. grain size = 285µm
Conchoidally fractured beryl grains (sparse yellow staining). Very pure 100% beryl. G. Swayze.
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2_3_4_ # HS180.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2_3_4_ # HS180.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2a3a4a # HS180.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2_3_4_ # HS180.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2_3_4_ # HS180.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns