Historical opal literature - an extract from Dana's Mineralogy
The following pages are an extract from this more historical text book of mineralogy. Written in 1962 it provides an window into the thinking and knowledge of the time, it is provided here as an example of mineralogical thought prior to the discovery of the structure of precious sphere type opal as revealed only two years later in 1964 by Australian Scientists, Segnit, Jones, Gaskin and Darragh. It may be considered that this is most likely the best up-to-date description of the mineralogy of opal for its time.
A journal article from Gems and Gemmology on the occurrence of Precious opal in Ethiopia
In this Article, Neville Curtis and his colleagues discuss new information regarding the mineralogical varieties of opal
The article in this issue of the Australian Gemmologist was for its time a ”land breaking” discussion on opal nomenclature.
The article in this issue of the Australian Gemmologist was for its time a ”land breaking” discussion on opal nomenclature.
