My periodic table poster is now available! Spark plug. According to this interesting article about different elements in spark plugs, and Bosch's own website these spark plugs use yttrium in the electrodes to increase the useful life of the plug. (The main constituent is platinum as in ordinary long-life plugs.) Given that common platinum spark plugs already last longer than some cars, is this really necessary? I don't know, but the electrode configuration sure looks cool. Source: Auto Parts Store Contributor: Theodore Gray Acquired: 10 January, 2003 Text Updated: 11 August, 2007 Price: $5 Size: 3" Purity: <1% Sample Group: Spark Plugs