Nacrite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Phyllosilicate

Sample ID

GDS88

Collection Locality

Nayarite, Mexico

Spectral Purity

1c2_3_4_ # GDS88 # 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 Kaolinite, Dickite, and Halloysite. IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 6.5-9.5 keV File: nacrt.out, -.mdi References: JCPDS #16-606 Found: Nacrite; probable minor dickite; unidentified weak reflection at 2.80 Angstroms Sought but not found: Kaolinite Comment: The pattern closely matches that of nacrite (a polymorph of kaolinite). The (002) reflection at 7.2 Angstroms did not expand following glycolation. Of four reflections that are not nacrite, three (4.27, 3.79, 3.50 Angstroms) are in the position of dickite (another polymorph of kaolinite) J.S. Huebner, J. Pickrell, T. Schaefer, written communication(USGS)

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126