All natural aroma therapy crystals are Altantic sea crystals infused with Très Spa synergy blends of Bring the essence of nature into your home. Très Spa all natural aroma therapy crystals are Atlantic sea crystals infused with Très Spa synergy blends of pure essential oils. We use 100% all natural therapeutic grade essential oils and cosmetic grade mica for color. These crystals are non-toxic, eco friendly, and are the perfect green alternative to candles, potpourri, or diffusers for air freshening. An added benefit to the Très Spa Aroma Therapy Crystals is their ability to provide natural true aroma therapy due to the fact we only use only 100% pure essential oils. While the salts are tub safe, we do not recommend using them in the bath as the mica may leave behind traces in the bath tub making it imperative to clean after use. Recommended use Place a few crystals in a glass dish and allow the aroma of the pure essential oils fill your living space. Great way to show the shimmering sparkle. Stir to refresh. Place a few crystals in a diffuser, add a little water and light the tea candle. Great way to show the shimmering sparkle. Stir to refresh. Simply open the tin and enjoy. Stir to refresh. For your car, either place the tin under your car seat open and enjoy or add a few to a muslin or organza bag and place in your car. Stir to refresh.