Fibrous structured amorphous silica including precipitated calcium carbonate, compositions of matter made therewith, and methods of use thereof

A coating composition for coating paper, paperboard products, or label stock, said coating composition comprising a water slurry including

• (a) a nano-composite material said nano-composite material comprising a fibrous amorphous silica component, said fibrous amorphous silica component provided in three-dimensional haystack or globular configuration that presents a fibrous structure having interstitial spaces between amorphous silica fibers with inner layers and outer layers with irregular interlacing amorphous silica fibers or filaments which are fixed in relation to each other, and a crystalline calcium carbonate component, said crystalline calcium carbonate component comprising aragonite needle structures, said aragonite needle structures arising from said fibrous amorphous silica component, said nano-composite material having a major axis of length L in the range from about 10 microns to about 40 microns and a surface area of from about 40 meters squared per gram to about 200 meters squared per gram;
• (b) clay;
• (c) one or more binders, said one or more binders including a selected latex, and/or including a selected protein;
• (d) said coating composition, after mixing, passing through a screen of selected size.