Screenwriter and film producer Bruce Joel Rubin, who once lived in a Tibetan Buddhist monastery, considers his 1990 film Jacob’s Ladder a modern interpretation of the Bardo Thodol.- Flint (Wikipedia)
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires.