Where is the glass blowing tour mentioned by Rick Steves in his Italy book? It’s near Piazza San Marco. Thanks!
Glass blowing tours are on the island of Murano. Get there on a vaporetto.
Donna, you may be thinking about a shop that provides a brief glass-blowing demonstration + showroom for purchasing versus a "tour". I believe the name is (or was) "galleria San Marco," and here's a TA review from 2018 that describes the location and mentions that it appeared in their Rick Steve's guidebook.
Here's a previous RS forum thread on the subject:
https://community.ricksteves.com/travel-forum/italy/glass-blowing-demo-at-st-marks-square-venice
Problem is, their website (http://www.galleriasanmarco.it) is no longer active, and I can't find any reviews newer than 2018 so it may not even be there anymore. Maybe the name has been changed but I can't find anything on that either. Address was S.Marco 181/A 30124, Venezia.
All that aside, Sam is correct: you want to go to the island of Murano to explore glass blowing.
My wife insisted.
It turned out to be a big yawner. It turns out that Burano is far more interesting to visit than Murano.
If you want to see a first-class glass blowing demo, the Corning Glass Museum in Corning NY is excellent.