This is a Gemmy Kurnakovite, from Boron, California.  It weighs 4 g. and measures 3/4 x 5/8 x 1/2"     Kurnakovites came out of the Boron Pit in the late 50's, but not since then.  I stumbled onto a few more in Tucson, this year. 

Its tenacity is brittle and it ranges between 2.5 – 3 on the Mohs hardness scale. It is not soluble in water, though it will start dissolving in warm acid. Kurnakovite is usually colorless or white and either transparent or translucent.

Formula:

Kurnakovite - Metaphysical and Healing Lore

From Siri - Kurnakovite immediately gives you the sense that you are holding something very powerful and special. It is like there is a book of healing information enclosed within her. She reaches into the earth and then pulls up through the Crown Chakra with no effort whatsoever. She holds many many secrets that only a few will learn. She feels weightless and ethereal yet you get the sense she is the earth. She is a water energy. She begs you to ask the tough questions regarding your personal growth and the things we wish to hide from ourselves with regard to ourselves. When we don't face ourselves and our secrets, then we don't grow and evolve. She helps you to "look" inside and see the reasons and the lessons learned in each life so that we may let go of them as completed and move forward. She is a cleaner, but a cleaner of the mind and spirit much more so than the physical body. Kurnakovite is a very, very special crystal.
Kurnakovite also has the ability to remove heavy metals from the body (i.e., Mercury). When the body is removing heavy metals, it is exhausting and hard on the liver and kidneys. Go slow and steady. Once again, ten minutes a day is good.