Lazurite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Tectosilicate

Sample ID

HS418.1B, HS418.2B, HS418.3B, HS418.4B

Collection Locality

Chile

Spectral Purity

1b2_3_4_ # HS418.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS418.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2c3c4u # HS418.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS418.4B # 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

(Na,Ca)7-8(Al,Si)12(O,S)24[(SO4),Cl2Cl2,(OH)2(OH)2] Beautiful blue. Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 6.5-9.5 keV File: lazur418.mdi (smear on quartz plate) Reference: PDF2# 41-1393, 27-88 Found: Wollastonite 2M, lazurite or related species Comments: Wollastonite peaks are very sharp and show clearly resolved alpha1 and alpha2 components, suggesting excellent crystallinity and compositional homogeneity. Lazurite peaks are very sharp, but not as strong as those of wollastonite. Profile-based search-match returned 2M wollastonite, hauyne and lazurite-C as probable hits. The intensities of the hauyne closely matched the non-wollastonite reflections; those of lazurite-C did not. Subsequent manual overlay of the six wollastonite patterns in the PDF2 database onto the non-sodalite-group reflections in HS-418 indicates that the wollastonite is of 2M, not 1A, structure type. Of the two 2M patterns in the database, the observed peak intensities better match 43-1460. Only six observed peaks lie clear of the numerous wollastonite peaks. These six peaks are explained by a primitive cubic lattice; the cell edge, 9.08 Angstroms, excludes sodalite but leaves other members of the sadalite group, nosean, lazurite, and hauyne, or their solid solution, as a possibilities (see Deer and others, 1962). The structure type could not be determined.

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801