Yttrium Element Number 39 Y 

Aeschynite (Y)  is a rare earth mineral, contains elements Yttrium, as well as: Ca, Fe Th Ti O and Nb. The Thorium content makes this a hot rock, kept under lock and key. This is a nice glassy sample.

Yttrium is a transition metal  that is often considered a "rare earth" metal. Yttrium is found in RE bearing ore, and is also resembles RE metals in structure. Yttrium is one of the elements discovered in Ytterby, Sweden.

Yttrium has a few cool uses, such as YAG laser rods, I personally had YAG laser surgery on my eye once. YAG stands for Yttrium Aluminum garnet, there are also Yttrium Iron garnets or YIG. YIG and YAG garnets have various uses but not in Zen practice. Sorry I just had to.

Yttrium also can be used in alloys, and can make elements like Mo, Cr and, Zr have better workability. Yttrium also is used as a superconductor component, in a Yttrium Barium Copper Oxide material. Yttrium also can be used in CRT TVs as a phosphor component with Europium to make red colors.

Yttrium was found in moon rocks at high concentrations, it is created mostly  via S-Process (slow neutron capture) in giant red stars and released by supernova, sometimes it can be created in rapid neutron capture supernova events. Yttrium isotopes are common products of nuclear detonations and also reactors. One use for Yttrium isotopes (Y90) is in the medical industry both as a cancer med. and as surgical cutting tools. The isotope attacks cancer with -beta radiation, or rather electron emission.

Two chunky pieces of Yttrium, Yttrium is easy to purchase by the kilo  

Y 39 Metal,  AW:88.90585  MP:2779  BP:6037  D:9.472 

Zirconium Element Number 40 Zr

 Zirconium is a cool element called a refractory metal, because of its high melting point. the element is what a cubic Zirconium is created from in the form of Zirconium dioxide. The metal is a beautiful silver color. I bought 2 Kg of nice crystal Zr bar direct from China.

Because Zr is resistant to many chemical attacks, and has a high melting point it is used in crucibles, and furnace applications. Zirconium is so similar to hafnium they are  the most difficult two elements to separate, but small amounts of Hf are sometimes not an issue in Zr applications.

 Zirconium without Hafnium impurities is required for an alloy used for nuclear fuel rod cladding, because the cladding should have  low neutron capture, and Hf has a very high neutron capture, and would rob the fuel from the neutrons needed for fission.  

One issue of Zr in nuclear application is an exothermic  reaction with water and steam at higher temperatures. The reaction can produce Hydrogen atoms and  gas which can cause blisters on the cladding. The blistering is caused by Hydrogen embrittlement, where Hydrogen atoms enter the metal and crack it. Hydrogen gas build up is also explosive, and can blow up inside buildings. This happened at the Fukushima facility, when it was damaged by the storm.

Zr has a few other cool uses, Zirconium oxide makes a heat resistant ceramic, used in crucibles and also abrasive.  Zirconium is used in re-entry parts of space crafts, because of its high melting point.  It can be used In medicine as a positron emitter.

 This photo is of 1 Kilo of pure Chinese Zirconium crystal bar. These bars are uncommon and very interesting.

 Zr 40 Metal,  AW:91.224  MP:3371  BP:7968  D:6.52  Mohs:5.0