Under y0 Ore's

When I was Exploring Caves Under y0 i found Diamonds and Lapis and after digging them I went deeper into the Caves for more Exploring and it took like 15minutes and I went back and saw the same Diamond's and Lapis that I broke. I'm 100% sure that I Mined them! It's like Regenerated them. I don't have the Proof because I didn't know that it will happen. And 1 more thing that I saw Enderman Holding Red Mushroom, I don't think that's normal but still I'm saying.