Iridium1
- Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). (wikipedia.org)
Mercury1
- Chemical Elements words: mercury to platinum, part 5 of 8. (wordquests.info)
Rare2
- Palladium, one of the rare metals, was first separated from native Platinum by Wollaston in 1803, and Was named after the planet Pallas, which had been discovered just before that time by Olbers. (materiamedica.info)
- Ore deposits of palladium and other PGMs are rare. (wikipedia.org)
Form1
- Platinum and Palladium, both proved in dust form, showed such similarity in their effects that the question arose whether corresponding differences might be found. (materiamedica.info)