What type of sealers protect against stains on outdoor stone and can withstand constant sun?
If your stone is going to be under the UV Rays or dealing with different weather conditions, I would use the Heavy Duty Exterior Stone & Masonry Sealer, which has excellent water repellency. If there will be an area that needs more oil repellency in addition to water repellency, you could wait 24 hours after your first coat of Heavy Duty Exterior Stone & Masonry Sealer and apply one coat of Heavy Duty Stone Sealer or Impregnator Pro.