Snowflake Obsidian (black) is a volcanic stone that helps us rid ourselves of those old, unwanted patterns in our life, and is very protective. The Amazonite (green) assists us in filtering out the useless information that we recieve on the daily AND blocks a lot of the electromagnatic radiation that we get from cellphones, computers, etc that drains our vital energy. (Please see the crystal section of the website for a full description of stones, crystals and all their uses.) This is a seriously powerful combination. Approx. 8 1/2" on strong stretchy cord. Looks good for guys too.