The value depends on the glaze and the year.  The Flower or Seeding pattern comes in a variety of sizes and is a Van Briggle favorite.

This vase is 4.5″ tall and is in the Mulberry color:

The mark signed simply Ann Van Briggle Colo. Spgs. was used with high gloss glaze between 1955-1968.

Most Teco vases are stamped at least once with the Teco trademark and many vases are double or triple stamped. Teco was also routinely marked with the shape number.

This Stangl Pottery Base is for a Kingfisher (3406S) , and is signed by artist - VGF - Veta Garrison

Hampshire pottery typically has a white clay bottom.  This mark is incised: HAMPSHIRE POTTERY 18/1 & circled H

This piece is from 1895:

This pottery mark is 1897 Rookwood with artist’s initials LNL (upside down) for Elizabeth Lincoln.

This shield mark is from the Conta and Boehme Porcelain Factory in Germany - c. 1840.

This mark is from the MWG Westerwalder Neukeramik Factory in Germany circa 1904.  The vase sold for $500.

This Rookwood mark is dated XII or 1912.  The C.S.T stands for  artist Charles Stewart Todd.

xxx

The mark shown is a Square Ink Stamp “Keramis made in Belgium” mark.

The Artist signature mark “Ch. Catteau” for Charles Catteau (1880-1966) and D-943 for the Design.

The original store label reads “Ovingtons New York” and 91-363 written in ink.

The vase that had this mark sold for $800.