Since the early nineteenth century, diatoms have inspired, and even participated in art! This set of 10 pewter charm beads celebrates the beauty of these ecologically important microbes. A morphologically and phylogenetically diverse selection is represented, serving as an introduction to the scientifically important field of diatom classification. Great for scientists, educators and students in the many disciplines concerned with the study of diatoms! Cast in pewter Hole size: 4.8 mm (3/16 in) Suitable for standard charm bracelets. Dimensions vary. See scale photo for reference. Thickness ranges form ~8-10 mm. Weight: 5.2 to 5.5g (a US Nickel weighs ~5g)