I think this thread has not defined what the thread was about. ?
If the question was, " Is there some nature or existence of poison gas related to treasure deposits? " That again is not defined what the question is.
People are looking at this ass-backwards. Is the poison gas related to the treasure, is it found associated with it or is it found at times co-existing with it.
Gold in native form or or man alterate to be in common bar form, it in itself has no known mechanism of producing a toxic gas. Silver, while it will corrode and form silver oxides, sulphides, all of those forms are actually weak cleansing agents. Silver oxides and sulphides can, in quantities produce toxic vapors only in that the vapors exceed levels tolerated by the human body. Like breathing pure oxygen is harmful.
Conventional gem stones will not produce any toxicity.
The human body can TASTE silver and gold. Yes they have a taste.
Now, what is often found associated with treasure, that is a different matter. Is it the site in itself that is toxic, e.g. inside a tunnel that is a natural site with weeping oil, sulphur bearing mineral deposits, radioactive mineral deposits, a volcanic gas vent pipe?
Treasure deposits are often buried in a fashion to take advantage of man made and natural detracting properties.
Glowing lights and smells that come and go associated with treasure? Are we talking about things related to another dimension, the dead, spiritual as in Demonic? Those exist as well. I have been in such a tunnel in Bukidnon where there was walking pillars of light, the smell of food and or death would come and go inside the still air of a tunnel. Spirit harassment is common. The common forms of recognition is to include, temperature change in the air surrounding your body or the immediate vicinity. An odor or smell. I have smelled anything from cigarette smoke to perfume, gasoline and food. The smell is curious. We experimented to see if a single persons affliction by this was in a wide radius of the human body or just your immediate vicinity. If you stand still the odor is recognizeable. Walk very slow and it will stay in the immediate surface of your body, walk quickly or travel in open air and it is not detectable but stop immediately and it is there again. I suspect the odor is in fact not a electrical signal say in your brain but is in fact in the air. By moving, the air passes by your face and nose so the immediate air is changed so fast the spirit/demon is not able to implant the odor into it. We even sat still in a room, smelled the smell, turned on an electric fan that blew in our/my face and the odor or smell would be blown away. Turn off the fan and it would return or be smelled again. So it is not something inside your brain but a physical property of the air that you are "smelling". So what is the entity creating an odor in lets say thin air ??
REAL treasure hunters have seen these things. People who read books can learn from others who have done it. Or, they can rattle like an empty barrel (ever heard an empty 50 gal steel drum rolled down the street and you know what I am referring to. A lot of noise but nothing inside.)
Zobex