Possibly Chinese soapstone carved by automatic machine. Try scratching the bottom with your fingernail.
I see nothing in that shield that even appears to be a letter E or P. Looks like a badly stamped Kanji "letter".
The description at the beginning states early American smith's,but by the mid 1700's there were many who moved back and forth between Canada and...
Not sure if you have viewed this reference book,but could be helpful at some point ...................
Tooth pick
The far right mark looks like a "C" in an acorn.
@Dundun
Not having a "sterling" stamp means nothing. There were probably hundreds of thousands of sterling pieces sold/traded by the Hudson Bay Company in...
Depends on what you consider "modern",probably newer than the 1970's."diamond cut" and someone added the safety chain at a later date.
Hard to tell from a photo and there are stones which can look similar........
It's spectrolite
http://www.classicbrocante.co.uk/blog/glossary/what-is-damascene-jewellery/attachment/vintage-retro-mid-century-toledo-damascene-inlaid-madonna-mar...
I remembered the term for the inlay"pique". Used with paper mache,tortoise shell,bovine horn and probably other materials.
The top piece looks a little like metal "inlay" on paper mache.........
Do you have any silly putty/sculpey clay,try making an impression like a wax seal.
Separate names with a comma.