Susie — Welcome.
Cathy kindly provided the basics, but I am adding a few extra notes that you and your granddaughter might find of interest.
Note that the photograph shows the 3-Handled Salad Bowl on the wrong plinth by a different manufacturer. It was sold on its own, with Jobling's black 2535 waisted plinth, with the plinth and a jade flower block, and, rarely, as a centrepiece with the plinth, a jade nude lady and block. In jade, it was made from about 1933 to the late 1930s.
The manufacturer, James A. Jobling of Sunderland was and is much better known for Pyrex. You can find their "JAJ" trademark on old Pyrex ovenware.
These bowls sold wholesale ex-factory gate at 39/- per dozen (3/3 each) in 1934. To this you have to add delivery and the costs of the wholesaler and retailer, so the shop price was probably around 5/11 or 5/11½. The plinth was 8/6 per dozen, the flower block 5/6 per dozen, and the nude lady centrepiece figurine and block was also 39/- per dozen.
Jade was the most costly glass that Jobling produced at this time — simply because some of the ingredients were very expensive. Baker & Crowe, in their
A Collector's Guide to Jobling 1930s Decorative Glass provide the full ingredients list with percentages by weight for Jobling's jade:
Sand 61.73%, Soda Ash 13.82%, Potash 1.08%, Lead Oxide 9.42%, Alumina 7.49%, Quicklime 2.78%, White Arsenic 0.47%, Boric Oxide 0.27%, Fluorine 1.25%, Chlorine 0.31%, Sulphur Trioxide 0.91%, Uranium Trioxide 0.34%, Cupric Oxide 0.11%, Chromic Oxide 0.018%.
Apparently this is technically known as Uranium Moonstone. The minute amount of uranium in it flouresces under Ultra-Violet light, so the bowl looks very bright in direct sunlight. Looking at some nasty chemicals in the ingredients list you can understand why many small glassworks and studio glassmakers buy their glass as ready-prepared cullet.
If you want to read more, you should be able to borrow the above book through inter-library loan from your local library — or ask here.
Bernard C.
