The stone is garnierite, named for its discoverer, Jules Garnier, who found it in New Caledonia in 1864. It's a hydrated silica nickel ore which may have traces of other minerals, including peridot, serpentine, talc, or chlorite (among others). Since it is a mixture of various minerals, it doesn't have a clearly defined chemical or mineral composition, and it doesn't have a specific crystalline structure, it also doesn't have a defined lattice type like many other minerals.
However, it does exude a lovely, loving energy. Garnierite is a stone to help you discover unconditional self love. It can guide you to this by reminding you that you are Divine in nature and by connecting to that Divine part of yourself, you will rediscover you are infinitely valuable, valued, and loved.