Pretty soon he was using silicone rubber to make two-piece, high-quality molds of lenses, good enough to try a few casting shots with epoxy resin. [Zach] ran into a few problems along the way ...

Because epoxy resin dries so slowly ... to recreate another aspect of nature (the Earth itself). Just DIY some geode designs with colors you like, as demonstrated by @artisttilldeath on TikTok ...