Once dismissed as ugly ducklings, flawed and unusual stones are increasingly being championed by high-end jewelers.

Electrochemical Energy and Sensors Laboratory, Department of Green Energy Technology, Madanjeet School of Green Energy Technologies, Pondicherry University, Puducherry 605014, India ...

† Division of Chemistry and Biotechnology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan ‡ Research Center of New ...