Dolomite is a Calcium Magnesium Carbonate. (Calcite is Calcium Carbonate) It is quite soft physically so you'll need to cleanse with smudging or sound.

I find Dolomite to be a very unassuming crystal - sitting quietly 'behind the scenes' bringing a calm settled energy. It's a good crystal for dealing with irritation and frustration, helping to bring a little patience and peace. It is gently protective.