From: Kerr McGee Mine, Carlsbad, New Mexico, USA
Size: 5.2 x 3.3 x 3.2cm
Good blue halite specimens from Carlsbad are getting harder and harder to find since there hasn't been any mining there in years, so the supply has really become scarce. Luckily, we know a former employee of the mine who still has some excellent specimens in his posession, so we have been able to acquire quite a few exceptional pieces. There are basically two types of blue halite specimens that you'll see for sale: slabs and crystal cubes. The slabs are fairly inexpensive but still beautiful, but the crystal cubes like this specimen are what are most valued by collectors.
What we have here is a 1.3cm blue halite cube resting on a sylvite matrix, surrounded by regular clear halite. The blue cube is actually partially embedded in the clear halite, and there are additional, small blue halite crystals visible on the matrix through the clear halite. This may be a small specimen, but the quality is top because the blue color is saturated and consistent through the crystal cube. The clear halite is like glass providing a window through which you can see everything inside. It looks white and hazy in the photos due to the lighting, but in person it's as clear as glass. The blue halite is chemically the same as the clear halite - the color is not caused by any additional chemical elements in the salt.
The blue is actually a result of tens of millions of years of exposure to the radioactive potassium in the sylvite. This is the same potassium you'd find in a banana, and it has a half-life of a billion years, but over tens of millions of years of exposure it builds up and the atomic modifications to the crystal structure are what cause it to appear blue. If you were to dissolve it and let it re-crystalize it would look white just like regular salt.
Comes with a labeled acrylic display base.