You know, the trouble of reading so many things is actually remembering several years down the line what was read First that comes to mind is the electrical conductivity of gold. I know, it is an old example, but until the advance of technology, electrical conductivity was not something that was considered as part of the property of a mineral (I don't know if it is considered a proper property even now, melancthe would know better). I think my point is that even 10 years down the line the advances of technology will discover a property of a mineral or will look at the chemical composition and would be able to discover something that was not previously possible and that will become an added property or an addition to the write-up of the chemical composition. I am not 100% ready to dismiss minerals as something we can close the book on in terms of studying further.

As for other properties - if people want to believe that wearing a gem will help with an illness just based on the writings of ancient civilizations they can go ahead. To remove a fool's delusion is a Herculean task.