Each stone varies. Blue aragonite is often used for its abilities to aid in intuition, communication, meditation, increased emotional perception and psychic ability. It has a beautiful, soft blue color similar to that of Aquamarine and Larimar. This stone is particularly excellent for healers of all kinds as its vibrations are harmonious with reiki energies. This stone connects the throat and heart chakras and helps one speak the truth from their heart. 
Physically, blue aragonite can help with respiratory illnesses and inflammation within the lungs. This is very useful along with a breath exercise of some sort.