https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13966982![Optics: crystals exhibiting interference colours. Colour mezzotint [] by R.H. Digeon, ca. 1883, after J. Silbermann.](https://images.rawpixel.com/image_social_portrait/cHJpdmF0ZS9sci9pbWFnZXMvd2Vic2l0ZS8yMDI0LTAyL2xyL3djdXRhNnRiMnEtaW1hZ2UuanBn.jpg)
Optics: crystals exhibiting interference colours. Colour mezzotint [] by R.H. Digeon, ca. 1883, after J. Silbermann.
Original public domain image from Wellcome Collection
Public DomainFree CC0 image for Personal and Business use