Anthracite Mohs scale), its higher relative density of 1.3–1.4, and luster, which is often semi-metallic with a mildly brown reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed. Anthracitization is the transformation of bituminous coal into anthracite. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. The heat content
A Star Is Burns play in the opening moments of the episode is a parody of "U Can't Touch This" by MC Hammer. The opening of Bart's film "The Eternal Struggle" is a reference to The Amazing Criswell's narration in "Plan 9 from Outer Space". Barney's film contains references to "Koyaanisqatsi", and the music of the film, which was composed by Philip Glass. Barney's film also features musical selections from the aria "Un bel di vedremo" from Act II, pt. 1 of Puccini's opera "Madama Butterfly". In its original broadcast, "A Star Is Burns" finished 57th in the ratings for the week of February