This precious metal is nearly impossible to fabricate. When alloyed with some of the other metals in the platinum group, such as iridium or platinum, osmium is used in certain applications where extreme hardness and durability are required. A couple examples of these are for electrical contacts and for tips of high quality fountain pens. There are at least four types of titration. These are acid-base, redox, complexometric, and Zeta potential. Cupellation: This technique is considered the most exact, elaborate, and destructive method of assay and is best suited for gold bullion or stock. Also called fire assay, the method involves treating ores or alloyed metals under high temperatures and carefully controlled operations to separate gold from base metals (copper, zinc, or lead), which may be present in the ore. Of the different precious metals in the platinum group (which includes iridium, platinum, osmium, rhodium, and ruthenium), palladium is known to be the least dense. It likewise has the lowest melting point. Palladium is utilized in many applications because of its unique properties, some of which are provided below. Palladium as an investment commodity: Palladium is valued at around US$415 per troy ounce. Actually, this is much lower than its price of more than one thousand U.S. dollars per troy ounce in early 2001, when the automobile industry placed a high demand for the precious metal for use as catalytic converters. On the obverse of the Krugerrand is the face of Stephanus Jonannes Paulus Kruger, fifth president of the South African Republic (note the surname Kruger and the South African currency Rand were combined to give this precious metal coin its name). Also here are the Afrikaans and English versions of the name "South Africa", both inscribed in capital letters. General: Chemical Symbol: Rh Atomic Number: 45 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 9/ 5/ d Atomic Weight: 102.90550 g.mol-1 Electron Configuration: [Kr] 4d8 5s1 Physical: Density (near room temperature): 12.41 g.cm-3 Liquid Density (at melting point): 10.7 g.