If I were in your boots , I'd simply use a tripod-mounted digital camera capable of 10 mega-pixel or above (with a macro function) , for starters . Copyright the images , if you so desire .
Just burn a few discs of the images & put one or two in a safety deposit box .
I would also photograph the item with a 35mm SLR camera with a macro lens .
Have 3"X5" transparencies made , as needed (2 copies initially - 1 for 'showing' to appraisers/experts , 1- for archiving same as above ).
The electron-microscopic process would seem excessive , to me , at this point .
I know I'm giving advise here , mafreche ; I'm not trying to tell you what to do ... please know that it's only advise given freely , same as everybody else here .
Having delt with antiquities before ( and I think others here have too ) , and knowing that there are many pitfalls (both real & imagined) for those new to this specific realm ......... I suggest NEVER dealing with folks who have commercial interests 'in thier hearts' , until such time as you have actually determined exactly what you've got .
That being said ,
I'd suggest you consider putting conservation of your item high on your 'to do' list , right after provenance ...
