Presented by David Horton of Opal Horizon Ltd, at the 7^th National Opal Symposium held at Lightning Ridge in July 2011.

A study of potch by La Trobe University - Centre for Materials & Surface Science. LTU Microscopy. X Ray Fluorescence, Spectroscopy & Radio Carbon Dating. Delivered at the 7th National Opal Symposium.

‘Opal Formation and Microstructure’ University of Technology Sydney. Delivered at the 7^th National Opal Symposium held at Lightning Ridge in July 2011.

Full paper & figures, as presented by Dr. Simon Pecover at the 7th National Opal Symposium held in Lightning Ridge, July 2011. Featuring some very interesting images of Australian Opal vein textures, and how they have been formed.

This paper on the Syntectonic Genesis of Opal deposits in the Great artesian Basin was published in 1996 by Dr.Simon Pecover of Pan Gem Resources Pty Ltd. This original paper precedes his paper “Breccia Pipes, Fluid Pathways of the Opal Gods”.

Presented by Paul Thomas, University of Technology Sydney, at the National Opal Symposium 2009

Presented by Jan Domagala Dept. of Mines & Energy at the 2007 National Opal Symposium.

By John J Watkins, NSW Geological Survey - Department of Primary Industries. As presented at the 2007 National Opal Symposium held at Coober Pedy.

By Jack Townsend (President Gemmological Association of Australia -SA Div.), presented at the 2007 National Opal Symposium.

By Anthony Smallwood, delivered at the National Opal Symposium in Coober Pedy 2007.

A guide for visitors to the area, produced by Warwick & Margaret Schofield.

A New Model for the origin of precious Opal delivered by Canberra Chemist Byron Deveson at the 2005 National Opal Symposium.

By Brian Senior published in the AGSO Journal Of Australian Geology & Geophysics, 1998.

By B.R. Senior, D.H. McColl, B.E. Long, & R.J. Whiteley in the BMR Journal of Australian Geology & Geophysics 1977.

By Dr Simon R. Pecover,Managing Director - Pan Gem Resources (Aust) Pty Ltd, July 2005.

By David Horton, CEO of Opal Horizon, May 2001.