Found some insulators in Mom's basement. Pretty teal with embossing, HEMINGRAY-42. Should I pitch this along with the others? It has no cracks, appears to be fully intact--with little"saw-teeth" like on bottom. Thanks!
The Hemingray Glass company mass-produced the No 42 by the millions starting around 1922. Sounds like yours is aqua glass and would have been made before around 1930. After that, they were (more or less) clear until production ended in the 1950s.
Both Western Union and Bell Telephone adopted the No 42 as their standard for long-distance lines, so you can probably imagine how those two enormous companies would have used a lot of insulators. As a result, the Hemingray 42 is probably the most common glass insulator found today.
No reason you can't clean it up and enjoy it in a sunny windowsill as a little piece of history, but the monetary value is near zero.