Briar, clay, ceramic, corncob, glass, whale bone, metal, porcelain, stone, wood. Sure.
In all my years of boarding school, I never saw this one. I wonder if Sir Walter Raleigh made these.
This is also called a chillum, a smoking pipe originated in India.
Be forewarned: it helps if you like Cat Stevens (born Steven Demetre Georgiou), now a.k.a. Yusuf Islam.
Oh, about that 420 code and the etymology of the most famous beeper code? Snopes debunks all the exciting origins. Jimi Hendrix didn't die on April 20, nor is it the LAPD radio code for marijuana smoking in progress. It's purpose is, clouded... in a purple haze, if you will.