Blue John may refer to:
- Derbyshire Blue John, a form of fluorite mined in Derbyshire, England
- Blue John Cavern, a cavern in Castleton, Derbyshire where fluorite is mined
- Blue John Canyon, a canyon in Utah, United States, site of the Aron Ralston accident
- Blue John (album), an album by organist John Patton
- Lance-Constable Bluejohn, a character in the Discworld series, a member of Ankh-Morpork City Watch
- Blue John Gap, a fictional location in Arthur Conan Doyle's short story "The Terror of Blue John Gap"
Famous quotes containing the word blue:
“Mozart has the classic purity of light and the blue ocean; Beethoven the romantic grandeur which belongs to the storms of air and sea, and while the soul of Mozart seems to dwell on the ethereal peaks of Olympus, that of Beethoven climbs shuddering the storm-beaten sides of a Sinai. Blessed be they both! Each represents a moment of the ideal life, each does us good. Our love is due to both.”
—Henri-Frédéric Amiel (1821–1881)