This glitch has happened a few times now, and this time I caught it. What happens is as I break some blocks, I begin to see some iron, then diamonds, redstone, lapis, obsidian, and various other blocks all in one space. http://imgur.com/LWRoOFF This isn't a mod and im not a hacker, because once I try to mine them I get nothing, and they disappear being replaced by stone. do any of you experience this too? Side note: my laptop is somewhat laggy This may not be the best example because theres only a few blocks, so if I get a better one I will post it.
For anyone wondering. Part of the way minecraft works is to send every single block in the loaded chunk to the player. This is what enables Xray plugins to work. Part of one of our plugins replaces the information for raw stone to random valuable blocks. This causes Xray plugins to pick up almost every block in a map as valuable, and makes them almost entirely unaffected. When a block is uncovered the correct block is sent as an update to the relevant clients in the area. If you see the blocks there is nothing to worry about, and it just indicates the update hasn't arrived at your client from the server. If this persists for a short time then reconnecting, or teleporting away and back again will reload the chunk and update you.
Also for updating your chunk while you are in it, press "F3" and "A" at the same time. This reloads all your chunks in your render distance. This also helps when you spawn in and chunks wont load.