Development of GlassCeramics Based on Ash Rock Yu HaihuGlassceramics in which wollastonite is the primary crystalline phase were developed based on ash rock.White or light yellow glassceramics were obtained from high CaO content glasses which exhibited bulk crystallization while heat treated,and substances with the appearance of natural marble were prepared by sintering the particles of low CaO content glasses. High CaO content glasses obviously separated during heat treatment,and the phase separation is favourable for bulk crystallization.The particles of low CaO content glasses were completely sintered before the glasses heavily crystallized,and the needleshaped wollastonite crystals formed first from the edges of glass particles and then grew towards the centers.: ash rock; glassceramic; wollastonite; casting; sinteringYu Haihu: Lect.,School of Material Science and Engineering,WUT,Wuhan 430070,China.