The second edition of Jenny's 1967 seminal book on the topic is full of nature-induced mandalas
Generally the study of wave formations—specifically sound—Cymatics looks at the mesmerizing organic shapes created by invisible waves. Founded by Swiss doctor and scientist Hans Jenny who used simple sine waves to create patterns in powders, liquids and pastes, the book collects images developed over 14 years. The resulting mandalas reference art (like the work of Herwig Weiser, architecture, geometry and nature, among other disciplines.
The second edition of Jenny's 1967 seminal book on the topic is as much eye candy as it is a resource for anyone interested in Cymatics, including photos as well as carefully documented accounts of his experiments with vibrations and frequencies.