Hi brhodes,
Welcome to Blade Forums. I hope you enjoy it here.
I am going to give this a stab off the top of my head without hitting the books. I am sure others can fill in the gaps or correct me.
Some of the handle material you mentioned is more applicable to production knives with that some of the terms are what I would call marketing terms. Those include:
Vintage Stag - If I am not mistaken is a term Case has employed in the last few years. It is their premium stag that they use on their production knives.
Red bone stag is bone dyed and most likely jigged bone typically found on, but not limited to traditional slip joint pocket knives.
Stagalon is a soft plastic (as opposed to hard) of some composition that gives a little and is died and formed to look like stag.
2nd cut stag is another production term that has a tendancy to be smooth and of a more uniform color unlike the outer part of stag that has more figure and color.
2nd cut bone stag is pretty much the same except it is bone rather than antler.
Genuine Stag could be any type of antler that looks good on a knife
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Red Stag was found on older Case knives and a few recent limited runs. In some cases the stag is dyed a reddish color.
While we are at it tourched stag is also a term used where some of the "valleys" of the figured stag is actually torched or lightly burned.
I better stop before I drive Les crazy here.
Most of the rest of the terms could be applied to custom knives as can bone.
Sanbar stag is native to India. It is in my opinion the most beautiful stag along with some antique european highly figured stag. There is now a ban on the export of Sanbar stag. Even though these antlers are shed and could be harvested a problem arose where the deer were being harvested for the antlers. If this type of stag is used on a knife it is usually called by name. As a rule when the term "Stag" is used in relation to a custom knife the assumption is typically Sanbar stag, but it is also found on some finer factory knives also on occasions.
Deer stag. Can really be any antler some look a lot better than others. Typically figured stag is desired over smooth.
Fossil stag. Most likely means fossilized Mamoth or Walrus horn or Ivory. I am not real familiar with the term and have not seen any true fossilized stag.
I hope this helps some and I am sure there are others with more information.
Bone is typically the shin bone of cattle dyed and jigged in various patterns. Some of us like it on certain knives others of us do not want cow bones on our knives and we have had a lot of fun with it over the years.
When I get a chance, I will get a pic of several examples up.
