Can I mine diamonds with TNT

Assuming the same laws of TNT in the PC/Mac game apply to the Pocket edition, then no, you cannot. By placing TNT, you will end up destroying the resources, so don't risk it.

However, since it will wind up destroying most dropped items, it is of no use in breaking blocks to collect their resources.

This is off the Minecraft Wiki under the TNT page: http://www.minecraftwiki.net/wiki/TNT

I suggest trying to find some iron and then mining it otherwise you will lose those precious diamonds. Do not try using TNT. If you have already, unlucky :(

No you cannot, you will just blow up your items.

Assuming the same laws of TNT in the PC/Mac game apply to the Pocket edition, then yes, you can!

However, there are two things to keep in mind:

1. 75% of the diamonds will be instantly "vaporized" in the explosion instead of dropped as items
2. You cannot use a Fortune enchantment when using TNT

Using those numbers, while using a Fortune III pickaxe to mine diamonds will net you an average of 2.5 diamonds per ore block, using TNT to mine will net you 0.25 diamonds per ore block.

So, although you can mine any ore with TNT, it's definitely not efficient (but could theoretically help out in a pinch).

With the TNT update, yes. Tnt will now drop every material it blows up. However, two things to think about: One: TNT will blow up any item on the ground. So your first tnt will drop everything. And if the diamonds are not picked up before the second TNT explodes, they will disappear. Two: You can use a Machine Bore to mine diamonds very efficiently with TNT: I suggest searching Ilmango tunnel bore machine on youtube for a more detailed explanation.