Violin, Cello & Bass Shell Slide liners, dots and ebony slide liners.
As a brief guide I will make the following, brief statements:
The French The Peccatte school would have, for the most part, been using the Ormeau. This is a member of the Haliotis family that lives off of the coast of North-Western France. It often has a small, tight flame that runs through the shell. It is a very small shell, making it difficult to get pieces long enough tio make a slide. I believe that it was generally worked along the natural curve of the shell and then flattened. Its main value today is due to its historic use and would otherwise be considered too marginal.
The Pajoet school around the same time was using the green abalone from what is now Baja and Southern California. They favored the piece from the inside and around the muscled scar—i.e. the heart—of the shell.
Viorin to modern day French use, for the most part, the Awabi shell from Japan. Japan was reopened fto Western trade in 1853.
The English... such as the Hills were, for the most part, using White Mother of Pearl for their standard bows. I assume this shell came from Australia due to their relations to the ex-pat felons living there. However, in fancy, Gold-mounted bows made by such makers as Tubbs you will sometimes see the "heart" of the black abalone.
The Germans... In their early bows were using, I believe, fresh water shells that are now either endangered or extinct. Makers such as Bausch would, at some times, use Green ab heart. In most of the 20th century their silver-mounted bows were fitted with very high quality green flamed abalone with most shifting to awabi in the latter part of the 20th century to the present day.
The American School... Is too promiscuous for the space and time available.