Australian Museum Journal Epigenetic common opal from the Hawkesbury Sandstone Formation of the Sydney Basin
- Shortform:
- Lovering, 1952, Rec. Aust. Mus. 23(1): 29–32
- Author(s):
- Lovering, J. F.
- Year published:
- 1952
- Title:
- Epigenetic common opal from the Hawkesbury Sandstone Formation of the Sydney Basin
- Serial title:
- Records of the Australian Museum
- Volume:
- 23
- Issue:
- 1
- Start page:
- 29
- End page:
- 32
- DOI:
- 10.3853/j.0067-1975.23.1952.619
- Language:
- English
- Plates:
- plate iv
- Date published:
- 16 June 1952
- Cover date:
- 16 June 1952
- ISSN:
- 0067-1975
- CODEN:
- RAUMAJ
- Publisher:
- The Australian Museum
- Place published:
- Sydney, Australia
- Digitized:
- 22 April 2009
- Available online:
- 22 July 2009
- Reference number:
- 619
- EndNote package:
- EndNote file
- Title page:
- Title page (141kb PDF)
- Complete work:
- Complete work (863kb PDF)
Abstract
An unusual occurrence of epigenetic common opal, apparently derived from the normal ground-waters of the Hawkesbury sandstone formation of the Sydney Basin, is described. The opal forms simple and botryoidal incrustations, simple and coralloidal stalactitic structures and also is deposited on stalactites of lamellar limonite. Refractive index values vary widely and haphazardly between 1.414 and 1.443.