925 silver.  The ring has an adjustable slide for perfect sizing. 
 
In alternate medicine, sugilite is known as the ‘healers stone’ because it balances the brain and is used for epilepsy and migraines. 
The purple stone is also said to have the ability to heal a mind troubled by stress and negative thoughts. Some believe sugilite crystals help us harvest more positive thoughts and feelings and to channel them towards a brighter outlook on life.