The Lava layer is mainly made of Igneous Rock and Hardened Lava with pools and cataracts of liquid Lava here and there. Patches of Sulfur blocks, Tourmaline blocks and Diamond Nodes are more infrequent components of the Lava layer. Rarely, Iron Nodes and even Lumite Nodes can reach into this layer.
While Tourmaline requires merely an equipped Stone Mining Cell to be mined, you will need at least an Iron Mining Cell to dig through Igneous Rock, Hardened Lava and Sulfur. Diamond Ore can be extracted from Diamond Nodes only with the help of Extractors of any kind. To scoop up liquid Lava, a Diamond Mining Cell (or Lumite Mining Cell) needs to be equipped (since update R62 on April 19th 2019).
Hot Feet and Warmworms are able to spawn in the Lava Layer during day and night on all blocks that are not illuminated by artificial lights or sunlight (if players should dig shafts leading down from the surface to the Lava layer). Hot Feet and Warmworms seem to be immune to fire, and Hot Feet can sometimes be seen crossing pools of liquid Lava unfazed.
Neither the glow of Hardened Lava blocks nor the brighter illumination of liquid Lava will hinder these Creatures from spawning. However, if Hot Feet are hit by sunlight, they will burn away in blue flames. Iron Treasure Chests are able to spawn on most blocks that the Lava layer is made of, unless in areas illuminated by artificial lighting (or sunlight, if you dig a large hole reaching from the surface to the Lava layer).
Sometimes, green Mirus will venture down into the Lava layer, and Keepas of any kind can also spawn there. However these Creatures can actually start to burn in time or when touching liquid Lava or staying on the Lava layer for too lng, which indicates that they too might have their own heat meters.
You can use Advanced TNT in order to dig downwards through the Lava layer too. Advanced TNT can destroy up to max. 11x11x11 (4 downwards, 4 upwards, 4 sideways + 1 block in the middle maximum each) blocks up to the hardness of Lava layer rocks including Igneous Rocks and Hardened Lava (since update R41 in April 2017).
Please note that Explosives like Advanced TNT and Super TNT cannot remove Nodes like Diamond Nodes, Coal Nodes, Iron Nodes or Lumite Nodes. An Extractor (or Advanced Extractor or Super Extractor) is required to extract the Ore from the Nodes. When you take the Ore, the Extractor is removed and the Node will be gone.
Super Excavators can remove blocks up to and including the hardness of Corrupted Blocks, so they can also remove Hardened Lava, Igneous Rock and all other removable blocks that the Lava layer is made of (excluding Ore Nodes). Super Excavators can also collect liquid Lava since update R62 on April 19th 2019. The Super Excavator will remove a large cube (7x7x7) of natural blocks, liquids, materials and crafted items, and will then save half of what they removed in Loot Bags that will fall down (or sometimes roll to the side).
Excavators are area-damaging "Explosives" just like TNT. The use/activation of TNT and Excavators alike, and even of Extractors, can be deactivated by enabling the game-world option "Disable Explosives" or by disabling the player claim option "TNT Enabled" if you're on your own player claim.
Temperature on the Lava layer is very high. The whole layer has a base temperature of 158°F even in areas where no hot rocks are near.
While one block of Hardened Lava usually has 111°F when stepping on it or touching it from the side in moderately temperated biomes, and only 85 °F when in cold biomes (before it turns into Igneous Rock), only one block of Hardened Lava alone can be up to 170°F hot on the Lava layer because of the high temperature of the surrounding.
Several blocks of Hardened Lava put together will usually be 152°F hot in moderately temperatured biomes, but only 115°F in cold biomes; however several blocks of Hardened Lava will be 180°F hot on the Lava layer when you step on them.
The hottest temperature in Creativerse can be experienced on the Lava layer when stepping directly into liquid Lava with 392°F, which will set player characters on fire immediately and deal burning damage over time.
Even though the bottommost 1-3 layers of the Lava layer often consist of Corrupted Blocks, these layers can still belong to the Lava layer, evident from the notification in the top right corner of the screen, so the air on these layers usually has 158°F - or even more if Hardened Lava and/or liquid Lava is very close.
The Stalactite layer on the other hand already has a base temperature of 86°F, but can get hotter when getting closer to the Lava layer, respectively closer to blocks of Hardened Lava and/or liquid Lava.
Just getting closer to heat-emitting Hardened Lava rocks or liquid Lava will already make a heat-scale show up that will then fill itself with red color for as long as you venture in this hot environment, until your player character will start to burn if no counter-measures are applied in time.
Liquid Lava has 392°F and will immediately set player characters on fire when they touch this hot liquid. This will not kill player characters right away though, but only in time.
If you place blocks of Snow or Ice into the Lava layer, especially on Hardened Lava or liquid Lava, they will melt into Water, which will also cool down and transform the hot blocks/liquid. Snow Cap blocks will merely turn into common Dirt blocks in the heat of the Lava layer.
It is advisable to stay away from pools of Lava, because as soon as player characters touch liquid Lava, they will immediately catch fire and suffer from fire damage over time for ca. 3 seconds even after stepping back. However liquid Lava is not instantly deadly, but usually leaves player characters enough time to find an escape or gulp down Basic Health Potions or Advanced Health Potions to stay alive.
If placed into liquid Lava, flammable materials like Leaves, Shrubs, Shredded Leaves, Thatched Walls, Wood blocks of all kind (even Corrupted Wood nowadays if placed in small amounts), Corrupted Leaves, Wood Walls, Wood Ladders, Wood Doors, Wood Tables and other wooden or vegetal blocks and items. Not every plant, block of plant origin or object made of wood is flammable though.
Mineral Water, Bog Water and Corrupted Water will evaporate if being placed on or next to liquid Lava in a small enough amount, otherwise the liquid Lava will harden into Hardened Lava instead. Molasses neither burns nor evaporates.
Throwing Freeze Bombs or placing Water or other Liquids except for the highly flammable Tar will transform liquid Lava into Hardened Lava, which will also happen if you liquid Lava into cool environments. To prevent Lava from hardening, you will have to heat up its surrounding by placing enough blocks of Hardened Lava together.
The hot Hardened Lava blocks will turn into Igneous Rock when they are cooled down - like when placing only a few blocks of Hardened Lava into cool areas or when hitting them with Freeze Bombs or Snowcubes. It might even be sufficient to just place ordinary Water, Corrupted Water or Mineral Water on Hardened Lava blocks in order to transform them into Igneous Rocks.
Hardened Lava will also turn into Igneous Rock when being placed into cool environments, which can be prevented by placing more blocks of Hardened Lava together. This will enable them to prevail even in cold biomes and can make them heat up the direct surrounding too.
In the overall heat of the Lava layer, blocks of Hardened Lava can set flammable solid blocks and items on fire, but not all of them start to burn equally easily. Hardened Lava can even set flammable blocks and items on fire in cooler biomes, but usually only if objects that operate with fire like Torches are being placed close by or even below the flammable objects/blocks.
How to deal with the heat on this layer
Entering the Lava layer or getting close enough to it will bring up a heat scale that will fill itself with red color. Upon full, the heat will deal burning damage over time to player characters as long as they keep on staying in this hot area.
In Creativerse, Armor does not protect player characters from heat damage and does not reduce it either; since armor only protects from physical damage.
In order to reduce the heat that the player character "feels", it is not sufficient to simply step on cooler blocks, since the whole surrounding (even blocks above the player character's head) is contributing to the total temperature that affects your player character. Also, the Lava layer has a base temperature that is sufficient to raise the heat scale all by itself.
To deal with heat meters, Fire Resistance Potions can be crafted and consumed. They will grant "immunity" to the heat for 10 minutes - indicated by the heat meter going down, vanishing and not showing up anymore for the whole time (even though the description only promises 90% reduction), and the potion will also reduce all fire damage over time (as dealt by Hot Feet, Warmworms or by touching liquid Lava) by half.
To reduce, negate or even reverse fire damage over time into healing effects, different kinds of Food can be cooked in the Cooking Station. Blazing Sandwiches and Blazing Pie will reverse fire damage into healing over time, but will not make the heat meter go away; both require liquid Lava as their main cooking ingredience.
An easier way to deal with the rising heat on the Lava layer is to simply dig ascending steps into any solid wall and such enter the Stalactite layer in order to cool down for a while before descending again after the heat meter has gone away.
Also digging downwards into the Corruption layer (as far as necessary for the heat meter to sink) is an option to flee the heat, however it is not advisable to stay close to corrupted blocks for too long, since Corruption will deal damage over time too as soon as the purple corruption meter will be filled...
A very convenient way to drop the temperature is to place a Snow Blower on the ground and stand on it, which will make the heat meter drop until it is gone. However, this will not help against burning damage over time dealt by the attacks of Hot Feet and Warmworms and by touching liquid Lava.
How to use
Both Sulfur and Hardened Lava can smelt 1 Obsidian Ore into 1 Obsidian bar in 10 seconds. It can also smelt 1 Iron Ore into 1 Iron Bar in 10 seconds. Sulfur and Hardened Lava can smelt 1 Diamond Ore to 1 Diamond bar in 30 seconds, and also 1 Lumite Ore to 1 Lumite bar in 30 seconds.
Diamond Ore is a valuable crafting material, used for high-tier armor and weapons as well as for furniture and precious building blocks.