> Figure 1, a photograph of actual snow crystals, not replicas, illustrates a striking example of two snow crystals which, if not identical, are certainly very much alike. ...
The two very similar snowflakes are in the bottom center of figure 1, side-by-side.
Ahh, found it. Nancy C. Knight, "No Two Alike?" Bulletin of the American Meteorological Society, 1988. https://journals.ametsoc.org/downloadpdf/journals/bams/69/5/... and available via https://scholar.archive.org/search?q=Nancy+Knight%C2%A0-+Bul... .
> Figure 1, a photograph of actual snow crystals, not replicas, illustrates a striking example of two snow crystals which, if not identical, are certainly very much alike. ...
The two very similar snowflakes are in the bottom center of figure 1, side-by-side.