FOSS gamedev and creative worlds

I have big deep 3 mines and i barely can find some redstone and diamonds. Once i dig and fell into lava so one parts were covered with cobblestone. I can't find any diamond, i have some redstone but diamond not at all . Where can i find them or if it's a problem how to fix it ?

redstone does not exist in Minetest; that is a Minecraft item. Diamonds are generally only found very deep underground, past a couple hundred nodes deep orso. The most sure way to find ores is to dig several long parallel tunnels one block wide and several blocks tall, which have stone no more than two blocks thick between them - that way, all ore blocks along and between the tunnels are exposed. Like this:

So long as you're several hundred blocks underground, using this method you are sure to find several diamonds within the first few minutes of digging - but it can become tedious after a while, and you will never need to go mine for cobblestone again because your storage will be always overfilling with it.

How about TNT ?

You craft TNT.

How do i do that ?

TNT is crafted by placing 1 gunpowder and 4 wood around it in a cross shape... Gunpowder is crafted by adding 1 coal lump and 1 gravel together...

Thank you. Let's do a big bang :D

And after usage of 10 TNTs,i was able to find a lot of diamonds. Thanks for help !