- Diamond Realty Hafa Adai & Welcome to Diamond Realty where our team of professionals can help you Buy, Rent, Sell or Manage Property. Our Realtors have Guam Covered! We specialize in Residential and Commercial Sales, Leasing, and Property Management. We are members of the National Association of Realtors, Guam Board of Realtors and the Multiple Listing Service. As members of the Guam Board of ...www.guamrealestate.net