Hello and welcome.
Your piece is sterling silver (.925 fineness ).
The D mark was used by William B. Durgin. Check here:http://www.925-1000.com/americansilver_D.html
46 is the catalog or pattern number.
34 is actually 3/4 which means 3/4 pint capacity of the piece.
E. Hertzberg Jewelry Co. was the retailer of the item.