The white howlite stone is believed to help teach patience, and overcome self criticism. It is also a very calming stone used to relieve stress of all kinds. It makes an excellent antidote to insomnia due to an overactive mind.
Zodiac - Gemini
Element - Air
 
Purple aventurine promotes psychic awareness, enhances motivation, and supports you to live as your authentic self.
Through meditation, purple aventurine can assist you to determine your highest purpose. It’s said to be a stone of choice to have with you throughout a job interview; as well it is known as a protection stone, and it supports you to recall and interpret dreams. Purple aventurine heightens creativity, and enhances musical skills for those that already possess them. 
Chakras - Crown