I hand cut this one of a kind focal bead out of a genuinely rare gemstone material called "Mohawkite."  Weight and measurements in the title, 2.5mm drill hole will fit most chains.  Chain NOT included.  Mohawkite is a VERY RARE metal mineral from the Copper Country of the Keweenaw Peninsula in the U.P. of Michigan.  It's referred to as a "discredited mineral species."  Upon its discovery in 1900 it was thought to be a NEW kind of mineral and was called Mohawkite for the next 70 years.  But when re-assayed in 1971 it was determined to be a combo of other things, mostly copper, algodonite, domeykite along with white quartz matrix.  The mine closed in 1932 and the mine dump has been picked over now for decades.  I have very little of this material to work with and rough material is very hard to find.  

This material does oxidize quickly but the shiny silver finish can be quickly returned with a simple rub with a polishing cloth. I do NOT put a layer of acrylic over my natural metal mineral cabochons to prevent tarnishing as some dealers do as I feel that a plastic sealant ruins the experience of the stone.  

Some metaphysical information I found on Mohawkite makes these claims… 
•the Stone of Divine Voice
•removes inner turmoil and self-loathing
•encourages one to work on and change negativity and corruption within
•can be used in ancestral healing as well as in soul cleansing
•connects to all physical chakras
•brings stability, balance and openness
•energizes, stabilizes and charges one’s energy fields so that one is balanced and aligned
•helps one to be open to the vibrations and emotional energy of others, allowing one to have empathy and honor others