# Brimstone chest

Brimstone chest
Released7 February 2019 (Update)
MembersYes
QuestNo
LocationMount Karuulm
OptionsUnlock, Check
ExamineIt looks as though only a special key would unlock this chest.
Map
Object ID34660

The Brimstone chest can be found next to Konar quo Maten on Mount Karuulm. The chest is locked and can only be opened by using a brimstone key, which is obtained from killing monsters that Konar assigns the player.

The exact odds of receiving the key are 1/100 for level 100 monsters and 1/50 for level 350 monsters, scaling linearly and capping at 350 as shown in formula 2.[1] For lower level monsters, it follows a curve: as shown in formula 1.[2]

{\displaystyle {\begin{aligned}P(L)&={\frac {1}{100+\lfloor (100-L)^{2}/5\rfloor }}&L\in (0,100)&&(1)\\P(L)&={\frac {1}{120-\lfloor L/5\rfloor }}&L\in [100,350]&&(2)\end{aligned}}}

${\displaystyle {\text{Where P is the probability of a drop and L is the monster's combat level.}}}$

## Possible loot

The following drop rates are provided by Jagex, unless otherwise specified.

The brimstone chest usually contains generic loot meant as a slight increase to the player's profits. There is also a rare chance of getting a broken dragon hasta, which can be repaired, for free, by simply showing it to Otto Godblessed (Barbarian Training in Smithing is not required for this). There's also a slim chance of obtaining pieces of the dusk mystic robe set, which come with a colour scheme similar to that of Mount Karuulm.

The average value of a drop from this table is 113,754.80.[3]

Item Quantity Rarity Price High Alch
Uncut diamond25–35 (noted)1/1269,500–97,3003,000–4,200
Uncut ruby25–35 (noted)1/1229,100–40,7401,500–2,100
Coal300–500 (noted)1/1243,800–73,0008,100–13,500
Coins50,000–150,0001/1250,000–150,00050,000–150,000
Gold ore100–200 (noted)1/1523,400–46,8009,000–18,000
Dragon arrowtips50–2001/1597,500–390,00015,000–60,000
Iron ore350–500 (noted)1/2049,000–70,0003,500–5,000
Rune full helm2–4 (noted)1/2041,268–82,53642,240–84,480
Rune platebody1–2 (noted)1/2038,533–77,06639,000–78,000
Rune platelegs1–2 (noted)1/2037,922–75,84438,400–76,800
Raw tuna[n 1]100–350 (noted)1/204,500–15,7502,400–8,400
Raw lobster[n 1]100–350 (noted)1/2015,200–53,2004,200–14,700
Raw swordfish[n 1]100–300 (noted)1/2028,300–84,9004,800–14,400
Raw monkfish[n 1]100–300 (noted)1/2022,400–67,20013,800–41,400
Raw shark[n 1]100–250 (noted)1/2066,500–166,25010,200–25,500
Raw sea turtle[n 1]80–200 (noted)1/2058,240–145,6009,600–24,000
Raw manta ray[n 1]80–160 (noted)1/2098,320–196,6409,600–19,200
Runite ore10–15 (noted)1/30111,630–167,44519,200–28,800
Steel bar300–500 (noted)1/30149,700–249,50018,000–30,000
Magic logs120–160 (noted)1/30127,320–169,76023,040–30,720
Dragon dart tip40–1601/30105,960–423,8406,000–24,000
Palm tree seed2–41/6076,104–152,208304–608
Magic seed2–41/60237,028–474,056506–1,012
Celastrus seed2–41/60159,942–319,884648–1,296
Dragonfruit tree seed1–41/60171,532–686,128258–1,032
Redwood tree seed11/6034,161390
Torstol seed3–51/60167,013–278,355126–210
Snapdragon seed3–51/60283,569–472,615108–180
Ranarr seed3–51/60182,085–303,47590–150
Pure essence3,000–6,000 (noted)1/606,000–12,0006,000–12,000
Broken dragon hasta11/20040,02837,440
Mystic hat (dusk)11/1,000120,7419,000
Mystic robe top (dusk)11/1,000237,03972,000
Mystic robe bottom (dusk)11/1,000226,14148,000
Mystic gloves (dusk)11/1,000104,7486,000
Mystic boots (dusk)11/1,000101,8976,000
1. The type of raw fish obtained is dependent on the player's Fishing level. The chance of rolling the fish drop is 1/20, after which the type is determined.

## Changes

For changes in the drop table contents, see here.
Date Changes
14 March 2019
(update | poll)

The brimstone chest now tracks the amount of times the player has opened it.

21 February 2019
(update)

Loot obtained from the chest is now broadcasted in the chatbox to players within the vicinity.

## Trivia

• Several items can be seen inside the brimstone chest while it is open, including piles of coins, stacks of bank notes, rubies, and vials of a yellow potion. This is a reference to the loot players can receive from the chest.

## References

1. ^ Jagex. Mod Kieren's Twitter account. 16 January 2019. (Archived from the original on 26 May 2020.) Mod Kieren: "It follows a curve up until level 100 then scales linearly between those 2 values upto level 350 combat. Creatures over thsi[sic] will cap at 1/50. [1]"
2. ^ Jagex. Mod Kieren's Twitter account. 16 January 2019. (Archived from the original on 29 April 2020.) Mod Kieren: "0.2*(CBLEVEL - 100)^2 + 100"
3. ^ Jagex. "Revised Post Kebos Poll Blog". 21 January 2019. (Archived from the original.) Old School RuneScape News.