I think Mojang should add volcanoes to Minecraft. They would be a very interesting addition to the game. If they wanted them to look realistic, they could simply look like mountains, however if Mojang want to make them look more like fantasy, they could be huge mountains of netherrack. Maybe even zombie pigmen or magma cubes could spawn there. It could be a little slice of the Nether in the overworld. They could have a massive tunnel of lava that goes straight from bedrock up to the surface where it pours out of the summit of the mountain. They could be super rare, around as rare as a mooshroom island or mega taiga, but it would still give the player even more reasons to explore the overworld.
People have also been wanting new ores added to the game, and what element likes to build up around certain volcanoes? Sulfur. Sulfur could take the form of either an ore close to the surface, or as dirt or stone that has a build up of sulfur (these blocks could have a yellowish hue to them). Mining them gives you sulfur powder, which could be made into sulfur blocks. My idea is that sulfur blocks deter undead mobs from a certain radius around the block, similar to how garlic works in fantasy books and movies. These blocks could be placed around your base to keep the zombies, skeletons, or phantoms away. Another use could be to make gunpowder. In real life, sulfur is used to make it, so why not in Minecraft too? Sulfur powder could be crafted with charcoal or coal to make it. Sulfur could be brewed to make potions that deter undead mobs from you, or give you fire resistance. It could also be used as fuel for furnaces. Since in real life, sulfur gives off sulfur dioxide-a toxic gas, when burned, it could cause you to loose health or give you poisoning around a certain radius of the furnace. To make up for this, sulfur could be one of the best fuels in the game, like a bucket of lava. If sulfur is added to the game, it would only spawn in volcanic biomes (similar to how emeralds only spawn in extreme hills, however it would be about as abundant as iron or coal), which would give you a reason to seek out volcanoes.
My next idea are Mineshafts that can spawn near the surface, but they are filled primarily with sulfur, obsidian, and lava. This would primarily be for aesthetics/adventure purposes, and don't necessarily need to be added. However, I feel like this would add some excitement to the biome.
My final idea are volcano specific creepers. Mojang could either make charged creepers much more likely to spawn here, or make a new variant of creepers all together. Zombies, skeletons, spiders, and slimes have all gotten variants for different areas of the game, and I believe that volcanoes would be the PERFECT chance for Mojang to give creepers a new variant. Here are a few ideas:
Creepers that have the explosion power of charged creepers, but do not drop the heads of mobs.
In fact I would like the sulfur you suggested to be made into sulfuric acid if mixed with water in buckets.
A yellow substance that could kill you if you remained in it too long.
The acid could be used as a trap device to kill mobs.
Now obviously it would be too hazardous to retrieve your items after their death in the moat of acid around your castle or village.
So to collect the drops you'd need to install a hopper system to put them into chests beneath the acid channels. A great way to defend your area against the pillager raids, right?
The caves and some water springs in the new volcano biome could also have sulfuric acid naturally occurring, adding even more danger to survival players to watch out for.
Also the sulfur dioxide you spoke of could be implemented near the pools of sulfuric acid and damage players who got too close to it, but not as quickly as it would damage you if you were actually in the acid.
The damage per second for being too close to the acid should be half a heart per second.
Being actually in the acid should be 1 heart per second, meaning in 10 seconds you die, even with full armour on.
I like the idea of hot springs you mention. In addition to your sulfuric acid idea: You could combine it with sugar to make coal, similar to real life.
and the acid should apply a poison status effect, which you already implied in your OP.
But only on normal or hard difficulty IMO.
on easy or peaceful it should still do damage, but leave no poisoning effect.
Giving the higher difficulty modes their literal meaning.
The poison status should be curable by milk, as it already is with the other poison sources like witch potions or cave spiders,
however the damage it does should be the same, take your health all the way down to half a heart until the poison is either cured or wears off.
If there was no poisoning effect for being too close or in the acid then it would be too easy to survive an encounter with the hazard.
In real life, sulfuric acid is actually non-toxic. However, it is very corrosive. There for I think a gradual loss of health would make more sense than a poison effect.
Then again, Minecraft is a fictional game about some dude named Steve trying to avoid exploding masses of moss and fight a dragon that is supposedly terrorizing a race of tall monsters that hate being starred at, all in a universe made of exactly 1 cubic meter blocks, so I guess anything can happen.
Well, sulfur dioxide can kill you because when breathed in it forms sulfuric acid after mixing with the fluid in the lungs, causing corrosion.
Either way it makes sense to have linger damage of some kind, there is no corrode damage currently in Minecraft.
So in place of that, if sulfuric acid, sulfur fumes and sulfur solid material were to be put into the game, it should cause a poison status when the player is exposed to it from getting too close to acid.
But I must clarify this one, the new material if it were implemented, should only be found in the new volcano biome.
If it were to exist anywhere else, it could make mining too frustrating for players.
The sulfur could also work as an indication that you were underneath a volcano or near one in the mines.
The sulfur ore shouldn't do anything harmful to you, only the acid and the fumes near it should.
This gave me an idea: What if it has the ability to degrade iron, chainmail, and leather armor until they break? Mojang could then implement a new type of armor that has the same characteristics as iron, however does not corrode. They could also implement this as an enchantment. And, if the air around the volcano is filled with sulfur dioxide, this could be a necessary thing to have when exploring. To protect your health, they could also add a potion or mask that allows you to explore the area without being harmed.
I think Mojang should add volcanoes to Minecraft. They would be a very interesting addition to the game. If they wanted them to look realistic, they could simply look like mountains, however if Mojang want to make them look more like fantasy, they could be huge mountains of netherrack. Maybe even zombie pigmen or magma cubes could spawn there. It could be a little slice of the Nether in the overworld. They could have a massive tunnel of lava that goes straight from bedrock up to the surface where it pours out of the summit of the mountain. They could be super rare, around as rare as a mooshroom island or mega taiga, but it would still give the player even more reasons to explore the overworld.
People have also been wanting new ores added to the game, and what element likes to build up around certain volcanoes? Sulfur. Sulfur could take the form of either an ore close to the surface, or as dirt or stone that has a build up of sulfur (these blocks could have a yellowish hue to them). Mining them gives you sulfur powder, which could be made into sulfur blocks. My idea is that sulfur blocks deter undead mobs from a certain radius around the block, similar to how garlic works in fantasy books and movies. These blocks could be placed around your base to keep the zombies, skeletons, or phantoms away. Another use could be to make gunpowder. In real life, sulfur is used to make it, so why not in Minecraft too? Sulfur powder could be crafted with charcoal or coal to make it. Sulfur could be brewed to make potions that deter undead mobs from you, or give you fire resistance. It could also be used as fuel for furnaces. Since in real life, sulfur gives off sulfur dioxide-a toxic gas, when burned, it could cause you to loose health or give you poisoning around a certain radius of the furnace. To make up for this, sulfur could be one of the best fuels in the game, like a bucket of lava. If sulfur is added to the game, it would only spawn in volcanic biomes (similar to how emeralds only spawn in extreme hills, however it would be about as abundant as iron or coal), which would give you a reason to seek out volcanoes.
My next idea are Mineshafts that can spawn near the surface, but they are filled primarily with sulfur, obsidian, and lava. This would primarily be for aesthetics/adventure purposes, and don't necessarily need to be added. However, I feel like this would add some excitement to the biome.
My final idea are volcano specific creepers. Mojang could either make charged creepers much more likely to spawn here, or make a new variant of creepers all together. Zombies, skeletons, spiders, and slimes have all gotten variants for different areas of the game, and I believe that volcanoes would be the PERFECT chance for Mojang to give creepers a new variant. Here are a few ideas:
I like the idea of hot springs you mention. In addition to your sulfuric acid idea: You could combine it with sugar to make coal, similar to real life.
In real life, sulfuric acid is actually non-toxic. However, it is very corrosive. There for I think a gradual loss of health would make more sense than a poison effect.
Then again, Minecraft is a fictional game about some dude named Steve trying to avoid exploding masses of moss and fight a dragon that is supposedly terrorizing a race of tall monsters that hate being starred at, all in a universe made of exactly 1 cubic meter blocks, so I guess anything can happen.
This gave me an idea: What if it has the ability to degrade iron, chainmail, and leather armor until they break? Mojang could then implement a new type of armor that has the same characteristics as iron, however does not corrode. They could also implement this as an enchantment. And, if the air around the volcano is filled with sulfur dioxide, this could be a necessary thing to have when exploring. To protect your health, they could also add a potion or mask that allows you to explore the area without being harmed.