抄録
Huge spiral crystals of potassium dichromate (K2Cr2O7)have been found to grow three-dimensionally in a gelatin medium when gelatincontaining K2Cr2O7 was dried slowly in a test tube at a lowtemperature.These spirals were all right-handed, and their widths, axial pitches andlengths were 2--3, mm, 5--6, mm and 20--25, mm, respectively. When the gelatinconcentration in the medium was decreased, ordinary platelike crystals were observed to grow, instead of the spiral crystals. To the best of our knowledge, inorganiccompounds such as K2Cr2O7 have so far not been reported toform such huge spiral crystals.It is conjectured that collagen molecules, which compose the gelatinmedium and have right-handed triple helix structure lead to the growth of spiralcrystals.
