Vintage/Antique Lithograph/Etching

I was going through through one of my storages and found this vintage or antique lithograph or etching.this item is inside a frame with frame measure 18"x24:, image measure about 9.2"x14,2",I can't make out name ,I tried to get a good picture.Any idea.Sorry for the light from my camera

 

Odd, it looks like a charcoal or graphite piece to me but I can't see close enough to tell. Still life like this were a common Drawing 101 assignment.

 

I looked at it with y loupe and it really does look like a charcoal.I haven't removed art from frame.

 

Cool! If those spots are foxing on the mat then you should disassemble it and put in acid free mat and backing... Then you could inspect it further. But if it's just spots on the glass that need cleaning then I'll understand why you don't want to break it open.