Obsidian is one of the craftable blocks in Minecraft Survival and it is used to make enchantment tables and nether portals.
To make Obsidian you just need Water and Lava Buckets. Please follow the following steps to make Obsidian Block.
In order to make obsidian, first of all you need to get water from the river or sea using a bucket.
The next thing you will need to find is lava. Look for the lava and take it in your lava bucket bucket.
And then find a hard surface of your choice and dig a hole by using your diamond pickaxe.
Then put a bucket of lava in this hole and cover it up with water as shown in the image below.
You will get an obsidian block in this hole, when water will pass over it. Use your diamond pickaxe again to collect it.