These green crystals are related to the heart chakra but can work well on healing throughout the entire meridian system and are often used in Reiki healing.  It has a rejuvinating effect on the mind and is believed to attract good luck and prosperity when carried or worn. It helps calm inflammations, and alleviate pain of joints and muscles as well as help regulate the heart and lungs. Traditionally it has been called the stone for farmers and those who work in nature due to its green coloration.  It's also connected to the devic realms and some using it to attract fairies or commune with the spirit realms. These pieces are un polished (raw) chunks about an inch or more in size.