Azulene (image) Shinshu University Share Print E-Mail Caption The blue color is hard to observe in its crystal form. Azulene emits an odor resembling mothballs. Credit Shinshu University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.