Iridium Element Number 77 Ir 

This tiny pellet of pure Iridium weighs a remarkable 2.5 grams. Iridium is one of  the rarest metals in the earths crust and second densest to Osmium.

 Ir 77 metal  AW:192.217  D:22.56  MP:4471  BP:8002  Mohs:6.5

 Iridium is a rare PGM (Platinum group metal) with a name that leads some to believe it is radioactive. Perhaps Iridium sounds sorta like irradiation. Iridium is the most corrosion resistant pure metal, but Iridium is also brittle and hard making it difficult to work.

Iridium is found more in meteors than the earths crust. There is a theory that a layer of the crust is higher in Iridium than other sections because of a super meteor impact event. Another reason some believe Iridium being scarce in the crust is that Iridium sank with Iron into the mantle and core of the earth when earth was molten.

Iridium is found in Platinum ores, and is processed out of Platinum as impurity. Iridium is used in a few special applications. Spark plug electrodes of Iridium are becoming popular. Crucibles of Iridium are used to make sapphires and GGG (Gadolinium Gallium  Garnets) because of the resistance to corrosion and high melting point. A native alloy of Iridium and Platinum is called  Platiridium.

Iridium is alloyed with Platinum to improve hardness in applications such as jewelery.  Osmium and Ruthenium Is alloyed with Iridium and used for fountain tip pen nibs, and special parts for compass and scales. Sunglasses and helmet shields coated with Iridium compounds are becoming popular.

The Kilo standard of the International bureau of weights and measures in France uses a Platinum- Iridium alloy, and at one time the Meter standard was also  Iridium alloy. The meter has been replaced by a spectral line formula of Krypton. Iridium black is a super black pigment used in glaze. When items glazed with Iridium black are viewed near other black glaze the others look pale.

Some super cool uses for Iridium is the coating on Chandra X x ray telescope. Anti protons can be achieved shooting  a high power proton beam into a Iridium target. Spinners for synthetic fiber production are made from Iridium, and Iridium is used as a catalyst in some applications. Ion engines in cool space craft with Plutonium.

Isotopes of Iridium include two native stable isotopes, and 34 or more synthetic radio isotopes. Iridium192 is a powerful gamma emitter, and used in a special cancer treatment application. This isotope can cause burns and death. Iridium192 can also be used in metal x ray testing.

 

Platinum Element Number 78 Pt 

This tiny sample of Platinum is gas vapor transport crystalline structure of high purity

Pt 78 metal  AW:195.084  D:21.45  MP:3214  BP:6917  Mohs:4.5 

A typical Platinum plated hard drive disc, the layer of Platinum is very thin. Some people purchase these on EBay for PGM recovery. This is most likely a difficult toxic low profit if any activity.

Platinum Is one of the more popular precious metals, and the name is associated with wealth and accomplishment.  Platinum is one of the rarest elements, and can occur in a native state. Platinum is a ductile and corrosive resistant metal, and has many uses in industry.

Platinum is used in expensive jewelry, usually in a alloy with Iridium. Platinum wedding bands and engagement rings are impressive, Solid Platinum chains are a serious show of wealth.

Platinum can also be found used in catalytic converters with other Platinum group metals. This has caused issues with scrap metal and thieves. I have seen hard drive platters and catalytic converters for sale on EBAY and sell for large sums. The HD platters have very thin Platinum coating, and the ceramic materials in exhaust systems is difficult to refine into pure metals. Backyard scarping is dangerous and usually a money losing endeavor. 

 some other uses of Platinum as a mirror coating, and data storage in most common hard drives. Platinum is used in electrical contacts, chemical catalysts, and is one of the few metals the US mints as bullion.

Platinum is expensive, nearly as expensive as Gold. I do not have many Platinum samples, I have a "blob" a micro crystal, and a few scrap items such as the hard drive disc. Some day when I am very wealthy I will buy a huge Platinum chain and upload the picture to this site.