In my late teens, Mom had a pair of Sage Green Wedgwood jasperware earrings that I admired, so she had them converted to pierced and gave them to me - so sweet! Not really a huge fan of the more common blue jasper, but I loved the soft green, it reminded me of the velvety underside of leaves, and so I started collecting it. Wedgwood jasperware is made from a dense, unglazed stoneware with a matte surface, usually decorated with white classical motifs that were cast in separate molds and applied to the base before firing. This is a #24 - 6¼" tall jug or pitcher, dating from between 1891 and 1908; it's a "dip" or "dipped" piece, referring to having a layer of one of the various colors of jasper over a white body rather than the body being "solid" colored jasper.
The Stoke-on-Trent/thepotteries.org website is a great resource for English pottery, with an informative page on Jasper Ware, Josiah Wedgwood Marks, and Dating Wedgwood. Another website has a Color and Date Guide to Wedgwood Jasper, and the Ceramics Today site has an interesting article on The Life of Josiah Wedgwood and his wares.
