While poking about the block textures and making John Smith image replacements I noticed that the stardust ore was 16 numbered images, presumably an animation of some kind. Minecraft usually tiles animated cells vertically into a single image and makes a .mcmeta file describing the animation.

That was until I saw a few examples of the ore... they are randomly chosen from the list of images. Interesting idea. I may have to get more creative than normal to make the full set.

Closing as answered.