"Yominum is apparently an element, symbol Ym. It is apparently radioactive, and presumably a heavy element. Spock input the correct molecular formula for yominum sulfide crystals in his training computer after undergoing the reblending of his katra with his body. (Star Trek IV: The Voyage Home) The element or its isotopes have not been mentioned before or since Star Trek IV. Yominium [sic] is derived from \"Nimoy\" spelled backwards. (Star Trek Encyclopedia)"@en . "Yominum is apparently an element, symbol Ym. It is apparently radioactive, and presumably a heavy element. Spock input the correct molecular formula for yominum sulfide crystals in his training computer after undergoing the reblending of his katra with his body. (Star Trek IV: The Voyage Home) The element or its isotopes have not been mentioned before or since Star Trek IV. Yominium [sic] is derived from \"Nimoy\" spelled backwards. (Star Trek Encyclopedia)"@en . . . "Yominum"@en . . .