Forma, Vol. 8 (No. 3), pp. 315-325, 1993
Original Paper

Crystal Forms of Quartz and Their Changes Induced by Growth Rate Ratios of Faces, m, R and r
—Drawing by Computer Simulation—

Hideo Iwasaki and Fumiko Iwasaki

Sobudai-Danchi, 1-6-15-12, Sagamihara 228, Japan

(Received July 28, 1993; Accepted November 9, 1993)

Keywords: Crystal Forms, Quartz, Crystal Growth, Growth Rates, Computer Simulation

Abstract. Crystal forms of bi-pyramidal quartz composed of faces, m, R and r, were drawn by computer simulation under the specific values of growth rate ratios, 1 gr(r)/gr(R) 2 and 0 < gr(m)/gr(R) 2. The simulated forms could be classified into 8-groups, specified by the numerical factor, N, evaluated from the relation, N = (R·r) + m, where R, r and m expressed the number of sides in 3-kinds of faces. Values of N corresponding to 8-groups are specified, respectively, by 0, 3, 5, 9, 13, 21, 27 and 31. The 8-groups are regarded as the whole of possible groups in classification of crystal forms of bi-pyramidal quartz composed of faces, m, R and r. The comparison between drawn and observed crystal forms showed reasonable correspondence.