We have used Crystalline Phoenix® selenite pieces from 5 pounds up to 1200+ pounds for indoor and outdoor gridding projects, with total amounts per project from 65 pounds up to 4000+ pounds. Amounts will vary depending upon the requirements of the individual space, be it a bedroom, an office, a residence, an agricultural area, an animals' home space, an industrial site, or a large ranch. We have found that animals appear to love selenite in their space. We use pieces from milky white to window glass clarity. For more detailed information on gridding and its many benefits, along with a list of projects to date, please go to "Projects". (See landscaping section for a sampling of pieces that are available for gridding projects. Contact us with specific requirements.)