Patent ID: 8394732

Claim:
A glass-ceramic body prepared from all natural raw materials by a process comprising: a) combining the natural raw materials white sand, kaolin and magnesite in relative amounts suitable to provide, upon subsequent homogenization and heat treatment, a mixture of oxides comprising from about 50 wt % to 60 wt % of SiO 2 , from about 25 wt % to 35 wt % of Al 2 O 3 , from about 8 wt % to 12 wt % of MgO, from about 2.5 wt % to 3.5 wt % of TiO 2 , and from about 0.5 to 1.0 wt % of Fe 2 O 3 ; b) melting the combination of natural raw materials at a temperature of from about 1500° C. to 1550° C. to form glass material and subsequently quenching said glass material; c) crushing said quenched glass material to frit having a median particle diameter of no greater than about 65 microns; d) consolidating the crushed glass frit into a body; e) sintering said body at a temperature of from about 1000° C. to 1375° C. for a sufficient time to devitrify at least a portion of the glass into a polycrystalline material; and f) cooling to provide a sintered glass-ceramic body comprising a polycrystalline material which is primarily cordierite.