That moment I found out 90% of Roman glass is actually green, not clear
I was reading through this old museum report last week from a dig site in London, and it completely threw me. For years I thought the Roman glass I saw in exhibits was just discolored from age, like your grandma's old Tupperware. Turns out, most of it was naturally colored green or blue-green because of iron impurities in the sand they used. The clear glass we think of as standard? That required much purer silica and special additives they only used for luxury pieces. I never realized how much modern glassmaking has colored my expectations. I mean, I've handled probably 50 shards at local archaeology club meetings and never once questioned why they all looked the same shade. Has anyone else stumbled onto a fact like this that made you rethink everything you saw in a museum?