From: 10th Ore Zone, Kerr McGee Mine, Carlsbad, New Mexico, USA
Size: 6.4 x 6.0 x 3.3cm (as displayed at 45Âº angle)
We love Blue Halite specimens from New Mexico! Good specimens like this are becoming more and more difficult to find because no new material is coming out of the mine. Here is have a single blue halite cube crystal with a small amount of Sylvite matrix and some white halite crystals. The color is absolutely tops - it's a deeply saturated, gemmy blue. The condition is excellent with no dings or other forms of damage. There are some natural contact points, mostly on the bottom.
The blue halite would have formed first - tens of millions of years ago. The surrounding Sylvite mineral contains radioactive Potassium 40 which has an incredibly long half-life of 1 billion years. This means the radiation is so low that geiger counters have a hard time even picking it up. Potassium 40 is also found in bananas, but the radiation is so low that it's harmless to ingest. That being said, over tens of millions of years this low radioactivity takes its toll on the halite, effectively altering the crystal lattice which gives it its blue color. The blue is not chemical - it's just a result of radiation on regular old table salt. The clear halite grew in more recently, and it hasn't had time to be turned blue by the potassium in the Sylvite.
The specimen comes with a labeled acrylic display base.