Zirconolites from Sri Lanka, South Africa and Brazil
Zirconolites, CaZrTi/sub 2/O/sub 7/, from Sri Lanka and Pala Bora, South Africa, and a calzirtite, CaZr/sub 3/TiO/sub 9/, from Jacupiranga, Brazil, were examined using the electron microprobe, x-ray diffraction (annealing study), transmission electron microscopy, scanning electron microscopy and optical microscopy. The x-ray data indicate that all three zirconolites are metamict. Both Sri Lanka zirconolites are amorphous to the limits of resolution of the electron microscope (approx. 10 A). The Pala Bora zirconolite is largely amorphous but contains isolated domains (50 to 200 A) of crystalline material which may be the result of post-metamict recrystallization and alteration. The only other significant evidence for chemical alteration was the lower ThO/sub 2/ concentration (1 to 2 weight percent) and slightly lower analytic totals for the rims of the Sri Lanka zirconolites. Upon annealing at 1130/sup 0/C for 5 hours, all three zirconolites recrystallized as microcrystalline aggregates. Refined unit cell parameters and volumes are consistent with published data for synthetic zirconolites. Both Sri Lanka zirconolites contain microvoids, spherical in shape, and 200 Angstroms to 2 microns in size. This porosity may be the result of helium accumulation arising from the decay of U and Th. The calzirtite was highly crystalline, exhibited no porosity, and was unchanged by the annealing treatment.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA); New Mexico Univ., Albuquerque (USA). Dept. of Geology
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5975749
- Report Number(s):
- SAND-81-2171C; CONF-811122-3; ON: DE82001908; TRN: 82-001912
- Resource Relation:
- Conference: Annual meeting of the Materials Research Society, Boston, MA, USA, 16 Nov 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
ZIRCONOLITE
ELECTRON MICROPROBE ANALYSIS
ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ANNEALING
CALCIUM OXIDES
CHEMICAL ANALYSIS
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
MINERALS
OPTICAL MICROSCOPY
POROSITY
QUANTITY RATIO
STRUCTURAL CHEMICAL ANALYSIS
TITANIUM OXIDES
ZIRCONIUM OXIDES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
DATA
DIFFRACTION
HEAT TREATMENTS
INFORMATION
MICROANALYSIS
MICROSCOPY
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
SCATTERING
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
580400* - Geochemistry- (-1989)
360603 - Materials- Properties