Black Tourmaline is one of many variations of Tourmaline. It is a 7-7.5 on the Mohs Hardness Scale. With that rating it is a medium to hard stone. It commonly forms with other crystals, such as, Mica, Quartz, and Aquamarine.
Black Tourmaline is believed to help emotional stability, relieve negativity and victim mentality, and embarrassment & anxiety. Also, believed to be strongly protective and boost vitality.
Beautiful stone for any mineral collection, energy healing, etc. Please note that the size, shape, and coloration of stones may vary from picture. Most average about .5-1.5".
Every rock and mineral are known to have multiple properties, attributes, and uses. There is a plethora of information available both online and in books.