Abstract: This invention provides a process for synthesizing compositions containing trioctahedral smectite-type clays which contain fluorine within their layer lattices. In particular, the invention provides a process for synthesizing compositions having mole ratios of Li, Na, Mg and Si, expressed as oxides, and F of:aLi.sub.2 O : bNa.sub.2 O : cMgO : dF : 8SiO.sub.2 (I)where 0.ltoreq.a<1.2, 0.ltoreq.b<0.6, 4.75.ltoreq.c<7, 0<d<4, o.ltoreq.a+b<1.4, and 5.5<a+b+c<8, and where c.gtoreq.6 when a+ b= 0.

Abstract: This invention provides a gellant which is a synthesized complex of a fluorine-containing trioctahedral smectite-type clay and an amorphous occluded phase selected from the group consisting of lithium hydroxide, sodium hydroxide, magnesium hydroxide, lithium oxide, sodium oxide, magnesium oxide, and mixtures thereof, the gellant having mole ratios of Li, Na, Mg and Si, expressed as oxides, and F of:aLi.sub.2 O:bNa.sub.2 O:cMgO:dF:8SiO.sub.2 (I)where 0.25.ltoreq.a<1.1, 0.ltoreq.b<0.60, 4.75<c<5.85, 0.5<d.ltoreq.3.5, 0.60.ltoreq.a+b<1.25, and 6.0 <a+b+c<6.65.