Basalt Deltas

Basalt Deltas
Structures	Nether Fortress
Features	Glowstone blob; Lava sea; Delta; Basalt columns; Blob
Blocks	Basalt; Blackstone; Magma Block; Lava;
Climate
Temperature	2.0
Downfall	0.0
Precipitation	No
Colors
Fog color	; #685F70
Grass color	; #BFB755
Foliage color	; #AEA42A
Dry foliage color	; #A38046
Water color	; #3F76E4
Water fog color	; #050533‌[JE only]; ; #423E42‌[BE only]
Water fog distance	15‌[BE only]
Vibrant Visuals
Atmospherics	Basalt Deltas
Lighting	Nether
Volumetric fog	Default
Color grading	Default

The basalt deltas are a volcanic biome in the Nether. It is filled with lava and magma cubes.

Description

The basalt deltas is the second rarest Nether biome, making up around 16% of the Nether by volume, and can generate next to any other Nether biome except for the crimson forest.

The rough and jagged terrain of basalt deltas is composed largely of basalt and blackstone and features numerous deltas, shallow pools of lava, and magma blocks, typically reaching depths of 1 to 3 blocks. The biome's fog is a dull lilac color, and ambient ash particles float through the air. Archipelagos with islands of different sizes can be found around the lava seas nearby. On the ceiling, glowstone blobs generate as usual. Both brown and red mushrooms still grow in this biome on top of the basalt blocks.

Nether fortresses and ruined portals can be found here. Nether quartz ore, Nether gold ore, and the rare ancient debris generate underground, but are more difficult to obtain due to the abundance of deltas and lava seas. Ore also spawns more frequently to compensate for the significantly reduced amount of netherrack in the biome. Bastion remnants are not present, making basalt deltas the only Nether biome to not feature them.

Magma cubes have a higher spawn rate in this biome than in any other biome. Occasionally, a ghast can be spotted. Like in all Nether biomes, striders wander the lava lakes, and sometimes spawn trapped in the countless deltas.

Mobs

The following mobs naturally spawn here:

In **Java Edition**
Mob	Spawn weight	Group size
Monster category
Ghast^{[note 1]}	⁴⁰⁄₁₄₀	1 (Max 1)
Magma Cube	¹⁰⁰⁄₁₄₀	2–5
Creature category
Strider^{[note 2]}	1	2–4

↑ Only 5% of spawn attempts succeed. Additionally, Ghast pack spawn is hard capped at 1.
↑ Adult striders have a 3.3% chance to spawn being ridden by a zombified piglin holding a warped fungus on a stick.

In **Bedrock Edition**
Mob	Spawn weight	Group size
Monster category
Magma Cube	100	2–5
Ghast	40	1
Creature category
Strider^{[note 1]}	1	2–4

↑ Adult striders have a 3.3% chance to spawn with a saddle. They are supposed to spawn with a zombified piglin with a warped fungus on a stick but they don’t due to MCPE-236161.

Sounds

Music

These music tracks play while the player is in the basalt deltas:

Title	Preview	Java Edition		Bedrock Edition
Title	Preview	Weight	Probability	Weight	Probability
So Below		7	63.64%	7	63.64%
Ballad of the Cats		1	9.09%	1	9.09%
Concrete Halls		1	9.09%	1	9.09%
Dead Voxel		1	9.09%	1	9.09%
Warmth		1	9.09%	1	9.09%

Ambience

Nether ambience plays while the player is in the Nether.


Name	Sound	Group
Basalt Deltas Ambience		Loop
Basalt deltas active 1 (Unused)		Loop Additions
Basalt deltas active 2 (Unused)
Basalt deltas active 3 (Unused)
Basalt deltas active 4 (Unused)
Basalt Deltas Basalt Ground 1
Basalt Deltas Basalt Ground 2
Basalt Deltas Basalt Ground 3
Basalt Deltas Basalt Ground 4 (Unused)
Basalt Deltas Click 1
Basalt Deltas Click 2
Basalt Deltas Click 3
Basalt Deltas Click 4
Basalt Deltas Click 5
Basalt Deltas Click 6
Basalt Deltas Click 7
Basalt Deltas Click 8
Basalt Deltas Debris 1
Basalt Deltas Debris 2
Basalt Deltas Debris 3
Basalt Deltas Heavy Click 1
Basalt Deltas Heavy Click 2
Basalt Deltas Long Debris 1
Basalt Deltas Long Debris 2
Basalt Deltas Plode 1
Basalt Deltas Plode 2
Basalt Deltas Plode 3
Basalt Deltas Twist 1
Basalt Deltas Twist 2
Basalt Deltas Twist 3
Basalt Deltas Twist 4

Data values

ID

Java Edition:

Name	Identifier	Numeric ID	Translation key
Basalt Deltas	`basalt_deltas`	`173`	`biome.minecraft.basalt_deltas`

Bedrock Edition:

Name	Identifier	Numeric ID
[No displayed name]	`basalt_deltas`	`181`

Biome definition

This section is a work in progress.

Anyone is encouraged to edit this page and add more content into the topic.
Additional note: To be converted to standard JSON tree view - see Forum:Include enchantment, biome and dimension definitions in the Data values section for project info

Press "show" to display json contents

{
  "attributes": {
    "minecraft:audio/ambient_sounds": {
      "additions": {
        "sound": "minecraft:ambient.basalt_deltas.additions",
        "tick_chance": 0.0111
      },
      "loop": "minecraft:ambient.basalt_deltas.loop",
      "mood": {
        "block_search_extent": 8,
        "offset": 2.0,
        "sound": "minecraft:ambient.basalt_deltas.mood",
        "tick_delay": 6000
      }
    },
    "minecraft:audio/background_music": {
      "default": {
        "max_delay": 24000,
        "min_delay": 12000,
        "sound": "minecraft:music.nether.basalt_deltas"
      }
    },
    "minecraft:gameplay/natural_mob_spawns": {
      "argument": {
        "spawn_costs": {},
        "spawns_by_category": {
          "creature": [
            {
              "type": "minecraft:strider",
              "count": {
                "type": "minecraft:uniform",
                "max_inclusive": 2,
                "min_inclusive": 1
              },
              "weight": 60
            }
          ],
          "monster": [
            {
              "type": "minecraft:ghast",
              "count": 1,
              "weight": 40
            },
            {
              "type": "minecraft:magma_cube",
              "count": {
                "type": "minecraft:uniform",
                "max_inclusive": 5,
                "min_inclusive": 2
              },
              "weight": 100
            }
          ]
        }
      },
      "modifier": "overlay"
    },
    "minecraft:visual/ambient_particles": {
      "argument": [
        {
          "particle": {
            "type": "minecraft:white_ash"
          },
          "probability": 0.118093334
        }
      ],
      "modifier": "append"
    },
    "minecraft:visual/fog_color": "#685f70"
  },
  "carvers": "minecraft:nether_cave",
  "downfall": 0.0,
  "effects": {
    "water_color": "#3f76e4"
  },
  "features": [
    [],
    [],
    [],
    [],
    [
      "minecraft:delta",
      "minecraft:small_basalt_columns",
      "minecraft:large_basalt_columns"
    ],
    [],
    [],
    [
      "minecraft:basalt_blobs",
      "minecraft:blackstone_blobs",
      "minecraft:spring_delta",
      "minecraft:patch_fire",
      "minecraft:patch_soul_fire",
      "minecraft:glowstone_extra",
      "minecraft:glowstone",
      "minecraft:brown_mushroom_nether",
      "minecraft:red_mushroom_nether",
      "minecraft:ore_magma",
      "minecraft:spring_closed_double",
      "minecraft:ore_gold_deltas",
      "minecraft:ore_quartz_deltas",
      "minecraft:ore_ancient_debris_large",
      "minecraft:ore_debris_small"
    ]
  ],
  "has_precipitation": false,
  "temperature": 2.0
}

Achievements


Icon		Achievement	In-game description	Actual requirements (if different)	Gamerscore earned	Trophy type (PS)
PS4	Other	Achievement	In-game description	Actual requirements (if different)	Gamerscore earned	Trophy type (PS)
		Adventuring Time	Discover 17 biomes.	Visit any 17 biomes. Does not have to be in a single world.	40	Silver
		Hot tourist destination	Visit all Nether biomes	Note: Can be completed if the player visits the biomes in different worlds.	30	Silver

Advancements

Icon	Advancement	In-game description	Actual requirements (if different)
	Hot Tourist Destinations	Explore all Nether biomes	Visit all of the 5 following biomes: Basalt Deltas Crimson Forest Nether Wastes Soul Sand Valley Warped Forest The advancement is only for Nether biomes. Other biomes may also be visited, but are ignored for this advancement.

History

Java Edition

Java Edition
1.16	20w15a	Added the basalt deltas.
	20w16a	Increased the number of lava lakes on basalt deltas.
	20w21a	Ancient debris and Nether gold ore now generate more often.
1.18	21w41a	The water fog color of basalt deltas has been changed from #423e42 to #050533.

Bedrock Edition

Bedrock Edition
1.16.0			beta 1.16.0.57				Added basalt deltas.
1.16.100			beta 1.16.100.54				The ceiling of basalt deltas is now made out of basalt, instead of netherrack.

Data history

Java Edition
1.18			21w37a				Prior to the removal of numerical biome IDs, this biome's numerical ID was 173.

Issues

Issues relating to "Basalt Deltas" are maintained on the bug tracker. Issues should be reported and viewed there.

Trivia

Basalt deltas have no unique mood-based ambient sounds in dark areas and instead borrow those of the Nether wastes.
According to Felix Jones, the basalt deltas biome has a subtle Easter egg that has not yet been found by anyone.^[1]
Much of the ambience in the basalt deltas resembles the clicking of a Geiger counter, used to measure radioactivity.
- During the ambience creation process, Brandon Pearce provided the keyword "radiation" to audio director Samuel Åberg,^[2] which may explain its purpose.
In Bedrock Edition, the basalt delta is the only nether biome that doesn't have a red water tint.

Gallery

Screenshots

Typical view of the basalt deltas biome
A Nether fortress in basalt deltas
A valley within the deltas
A ruined portal in basalt deltas
The border of basalt deltas and a warped forest
Another view of basalt deltas
Magma cubes in the basalt deltas
Basalt columns in the lava sea
Basalt columns in the air and on the ground
Small pieces of basalt and blackstone floating above the lava sea
A bastion remnant next to basalt deltas
Blackstone in basalt deltas
A basalt deltas single biome world in the Overworld

Historical screenshots

A basalt deltas single biome world before 1.18

Mojang screenshots

Some blocks placed in a basalt deltas
Fog in a basalt deltas
Terrain in a basalt deltas
Kai in a basalt delta holding shield with a banner and wearing trimmed armor
A Basalt Delta as it appears in Minecraft Dungeons

References

↑ "In 1.16 I put a really, really, REALLY subtle & obscure easter-egg/reference into the basalt deltas biome that is hiding there in very plain sight. If someone ever noticed it; the pay-off would be so underwhelming that they'd be angry they ever looked for it." – @Xilefian on X (formerly Twitter), February 28, 2022
↑ "Dev Diaries #2: Nether Sound" – Minecraft on YouTube

External links

Around the Block: Basalt Deltas – Minecraft.net on August 13, 2020

[Ghast-1] Only 5% of spawn attempts succeed. Additionally, Ghast pack spawn is hard capped at 1.

[Strider-2] Adult striders have a 3.3% chance to spawn being ridden by a zombified piglin holding a warped fungus on a stick.

[Strider-3] Adult striders have a 3.3% chance to spawn with a saddle. They are supposed to spawn with a zombified piglin with a warped fungus on a stick but they don’t due to MCPE-236161.

[4] "In 1.16 I put a really, really, REALLY subtle & obscure easter-egg/reference into the basalt deltas biome that is hiding there in very plain sight. If someone ever noticed it; the pay-off would be so underwhelming that they'd be angry they ever looked for it." – @Xilefian on X (formerly Twitter), February 28, 2022

[5] "Dev Diaries #2: Nether Sound" – Minecraft on YouTube

[note 1]

[note 2]

[note 1]

[1]

[2]

v t e The Nether
Dimension	The Nether
Biomes	Basalt Deltas Crimson Forest Nether Wastes Soul Sand Valley Warped Forest
Structures	Nether Fortress Bastion Remnant Ruined Portal Nether Fossil
Blocks	Netherrack Glowstone Lava Magma Block Blackstone Basalt Soul Sand Soul Soil Crimson Nylium Crimson Roots Crimson Fungus Weeping Vines Nether Wart Block Warped Nylium Warped Roots Nether Sprouts Warped Fungus Twisting Vines Warped Wart Block Shroomlight Nether Quartz Ore Nether Gold Ore Ancient Debris Nether Wart Dried Ghast
Mobs	Blaze Ghast Happy Ghast Hoglin Magma Cube Piglin Piglin Brute Strider Wither Wither Skeleton Zoglin Zombified Piglin