Ket I will try at some point but I can't use the model creator on my device so it will be a bit harder. That was another reason I was reluctant to do that without code ahah. Also, I already have only one custom block per rock, the seashell type and color is generated at random when the block is loaded and will display in the name, that's why I was thinking I could load the model with code. But a single overlay texture for all blocks works fine too.

I feel like the ideal result would be a few variants, with some blocks showing the whole seashell on the side, but it would take too much of my time to do so and I'm mainly working on my thirst mod right now, there's a lot to do there. If someone wants to fork/pr this I will upload the source (didn't upload because it's literally a single class) and they can have a go at making this work.

maybe you can reuse the bone dirt texture?

I think making a block that looks like a random bunch of shells and gives you a random shell drop is fine? Better than making a dozen custom blocks. You could use the import feature of model creator to just jam random shells/colors into the block sides. They would come out looking a bit like the juicy ores mod. 

I love the concept though, it's like a precursor to fossils :D

NAVAROME It looks just like cracked rock right now, might add a variant that has a hint of what's inside but the issue is there are so many colors and shapes of seashell and I don't want to make a texture for each of them. The other solution is with code, I might do that in the future.

pic of the ore?