Vivienne Richards adds to the comments of Dick Stark in the last e-mail blog.

Yes I agree with Dick’s comments. Venetian is light and does not ring like
crystal, being soda glass. I find it usually has a broken (unfinished) pontil.
Powell is crystal, usually has a ground (finished) pontil and is often smaller and
less “robust” looking than Steuben. Of course, as Tom Dimitroff points out, the
best determinate of Steuben is the shape index. If the shape is not in the line
drawing index, then you should assume not Steuben, until you can prove
otherwise.
Happy Holidays everyone!
Vivienne