Petrifaction of Plant Tissue in the Laboratory

Abstract

PLANT tissue can be petrified by impregnation with natural waters with a high concentration of dissolved silicate¹. This occurs commonly in springs issuing from volcanic deposits in New Zealand, Ireland and Yellowstone Park in America. The process is easily duplicated in the laboratory in the following way. Small pieces of plant material (1 cm³ or less) are placed in 250 ml. polyethylene beakers, 50–100 ml. of deionized H₂O (pH. 6.0, which is adjusted by dilute HCl) is added; after 5–10 min, 2–5 g sodium metasilicate (Na₂SiO₃ : 9 H₂O) is stirred into the beakers, which are then allowed to stand undisturbed for 12–24 h. The pH rises to 14. The material is then washed several times with deionized H₂O, allowed to soak for 30 min in 2 N HCl; organic material is removed by wet ashing, using boiling concentrated nitric acid (1 part) and concentrated chromic acid (1 part)².