[[1.7.10] Using a custom item to break a custom block]

First of all, i don't know if it's the right category. 

And i know 1.7.10 is no more supported but i think there might be some people still coding in 1.7.10.

What i want is "simple" to say but might be hard to code :

I want a item that can break a specific block. 

Exemple :

I can't break "Chocolate block" with my hands.

I can break "Chocolate block" with my custom stick.

 

I hope my demand is understandable.

Sorry if my english not correct , i'm French.

 

[[1.13.2] Json Model transparent bottom]

Hi ! 

I'm making a ressource pack with custom models, but in one of my custom model, the bottom of the block is transparent. 

I've read that the cause is "isOpaqueCube : true" , but i don't know how i can modify this in the .json file..
(Sorry for bad english)

 

Thanks for reading.

Have a great day.

Scouloune.