Jasperware, or jasper ware, is a type of stoneware first developed by Josiah Wedgwood, although some authorities have described it as a type of porcelain. It is noted for its matte finish and is produced in a number of different colours, of which the best known is a pale blue that has become known as 'Wedgwood Blue'. "Jasper" in this context refers to the mineral of that name.
Dating Jasperware 
Wedgwood jasperware can often be dated by the style of potter's marks, although there are exceptions to the rules:
- Before 1860: Mark is "Wedgwood". Usually accompanied by other potter markings and a single letter.
- From 1860-1929: A three-letter mark represents in order, the month, the potter, and the year. The year code starts mid-alphabet with the letter "O" for 1860, the letter "P" for 1861, etc., returning to "A" after "Z". For certain letters there are two possible year dates. Unfortunately these date codes were used quite infrequently on jasperware pieces. A single letter is more commonly found during this time period but it is merely a potter's mark and of no consequence for dating the object. 
- 1891-1908: Marks are "Wedgwood", "England", separated.
- 1908-1969: Marks are "Wedgwood", "Made in England", separated, or "Wedgwood England" on small objects like thimbles. After 1929 the typeface of the word "Wedgwood" is changed to sans serif.
- 1970–present: Mark is "Wedgwood Made in England" as single stamp
Belt clasp designed by Lady Templeton and Miss Crew for Josiah Wedgwood's factory. Jasperware, steel, tin. The Walters Art Museum
German Jasperware 
Jean-Baptiste Stahl developed his own style and techniques during his work at Villeroy & Boch in Mettlach, Saar, Germany. The name Phanolith was coined for this kind of jasperware. His work is praised for the translucency of the white porcelain on a colored background. JBS's work is known for its refined modelling and the vibrancy of its figures. He thus combined the benefits of jasperware and pate sur pate. A stand at the World's Fair 1900 in Paris was the first major public presentation of his work and gained him a gold medal. For this event, two huge wall plates were created with dimensions of 220 cm x 60 cm, each.
- "Jasperware vase and cover". Ceramics. Victoria and Albert Museum. Retrieved 2007-12-09.
- *PaulRado. An Introduction To The Technology Of Pottery. 2nd edition. Pergamon Press / Institute Of Ceramics. 1988.
- The Black Figure in 18th-century Art, David Dabydeen.
- Michael Herman, Wedgwood Jasper Ware A Shape Book and Collectors Guide 2003, p.16
- Birmingham Museum of Art (2010). Birmingham Museum of Art: A Guide to the Collection. London: Giles. p. 148. ISBN 978-1-904832-77-5.
- Wedgwood buttons, made 1785-1800, from the Victoria & Albert Museum jewellery collection.
- "Jasper Ware". Encyclopedia Americana. 1920.