The algae retardant roofing granules 1 wherein said microvoids in said second or outer layer have {HEAD ~ an average thickness} of from about 0.05 micron to {TAIL ~ about 0.5 micron} 
of to
The algae retardant roofing granules 1 wherein said microvoids in said second or outer layer have { HEAD ~ an average thickness } of from about 0.05 micron to { TAIL ~ about 0.5 micron }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL