Correspondences

Regarding Correspondences

I was recently researching different deities and one of the items I've looked up is the various correspondences that are said to be associated with a particular deity.  As usual most sites on the internet regurgitate the same information over and over again, many simply a copy/paste of work found elsewhere with a different background and some pretty pictures added.  In this particular instance I was looking up an Egyptian deity and one of the correspondences claimed to be associated with him regarding crystals and gemstones was Opal.  This threw me because despite a couple of brief references to opals in Greek and Roman literature I can find no evidence of opals existing in Ancient Egypt.  Even the references I've tracked down could relate to fluorite as much as opal.  I could be completely wrong but it definitely got me thinking about the correspondences that we accept as assigned to particular deities and where this information came from.

Some correspondences are easy, mythology and pictorial representations give us the various colors, animals, symbols etc that we assign to certain deities.  But then we seem to need to give flowers and fragrances and foods and days of the week etc and I start wondering where all this comes from.  I'm sorry the historian in me just finds it hard to believe that we can say that all these deities have these correspondences.  The best we can do is say, okay - this deity is a moon deity, associations with the moon also include x, x and x so we could essentially associate this with said deity in theory.  Which is fine, but specify that, I think a lot of people are under some illusion that this information exists for each and every deity and it doesn't, plus there is just a significant lack of resource acknowledgement in these areas to begin with.