Promethium Element Number 61 Pm

Pm 61 Lanthanide  AW:145  D:7.26 MP:1908  BP:5432

Promethium is a rare earth element with no known stable isotopes. Promethium is the rarest rare earth metal, and generally found in pitchblende, an ore of Uranium. When  thinking  of natural Promethium, it is  estimated  the earths crust has 560 grams of Promethium at one time due to fission of Uranium in pitchblende ore.Estimates of 4 out of 10 to the 18th power of Promethium atoms occurs by mass in pitchblende. (10 billion billion)

Commercial Promethium is man made in labs, or reactors by fission of U235 with thermal neutrons. Promethium can also be created with U238 with fast neutrons creating fast fission. Neodymium146 with thermal neutrons,  and Uranium Carbide targets can also be hit with protons in a particle accelerator. in all cases the result is Promethium 147.

Promethium has a few commercial uses, in nuclear batteries used in missiles. Promethium is used  in afterglow paints, as a replacement for Radium. Promethium is used in measuring equipment for metal thickness, and may have use in portable x ray devices.

Promethium can be seen on some websites in the form of afterglow product such as painted watch hands, and also small vials of Promethium paint. Because Promethium generally is a beta emitter, it actually is a lot less destructive to the phosphor scintillator materials, unlike alpha emitting radium. 

Promethium is sometimes indicated in stars by spectral line analysis. The three stars of note are HR,  HD 101065, and HD 965

Samarium Element Number 62 Sm 

Half a kilo of pure Samarium from China, a misunderstanding between myself and the sales rep. led to these small granules, as I had hoped to obtain a kilo of large chunks.  The metal is a bit ed but still nice.

Sm 62 Lanthanide  AW:150.36  D:7.52  MP:1962  BP:3261 

 Samarium is yet another rare earth Lanthanide metal. This element takes 40th most abundant in the earth's crust. Samarium is a moderately reactive metal that will slowly oxidize in air.

Samarium has some interesting uses in industries like nuclear medicine and nuclear reactor control rods. Samarium Isotope Sm153 is a cancer fighting drug component, and Sm149 is a neutron capture control rod component.

Samarium magnets are used in music equipment, and space craft. Samarium compounds can be used in industry involving decomposition of PCB's and plastics.

Laser rods doped with Samarium were used in dye lasers. Samarium is used in X ray lasers for holographics. Like other rare earth metals Samarium is used in flints for lighters.