Release date  22 September 2014 (Update) 

Members  Yes 
Quest  Plague's End 
Location  Prifddinas 
Examine  A crystal key can open it. 
The crystal key chest is a treasure chest located in Ivy Sophista's house in Taverley. A second chest is located in Prifddinas in the Iorwerth Clan district. The chests are locked and can only be opened by a crystal key. Attempting to open the chest without the crystal key yields the message: "This chest is securely locked shut." The crystal key is made up of a loop half of a key and a tooth half of a key; you can make the crystal key by using them with each other, or selecting the "Assemble" option.
Opening a crystal chest grants a variety of rewards, which always include an uncut dragonstone. The crystal chest in Prifddinas grants slightly better rewards than the Taverley chest. The crystal key sells for more than most of the rewards, making it generally more profitable to sell the key than to use it. The key is used once and disappears upon usage.
Rewards possibilitiesEdit
The chest loot always includes an uncut dragonstone, together with a random reward generated from 13 possible reward tables. Below are the values of the chest's contents, based on current Grand Exchange prices. Unless otherwise specified, all possibilities gives all of the listed rewards when obtained.
After an update, wearing a ring of wealth will increase your chances of getting a better drop.
It is only possible to obtain rune platelegs if you are a male character, and a rune plateskirt if you are female character.
Taverley chestEdit
Possibility 1  Fruit tree seedEdit
The expected value of Possibility 1 is 53,260, which is a profit/loss of 12,768 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Calquat tree seed  1  Common^{[1]}  3,798  
Papaya tree seed  1  Common^{[1]}  50,312  
Palm tree seed  1  Uncommon^{[1]}  173,402 
 ^ ^{a} ^{b} ^{c} With Possibility 1, you are guaranteed to get either a calquat tree seed, a papaya tree seed or a palm tree seed. Both the calquat and papaya tree seed have a probability of 5:11 (45.45%), and the palm tree seed has a probability of 1:11 (9%).
Possibility 2  Lantadyme seedsEdit
The expected value of Possibility 2 is 14,029, which is a profit/loss of 26,463 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Lantadyme seed  2  Common  1,128 
Possibility 3  Grimy torstolsEdit
The expected value of Possibility 3 is 21,845, which is a profit/loss of 18,647 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Grimy torstol  2  Common  8,944 
Possibility 4  RunesEdit
The expected value of Possibility 4 is 116,051, which is a profit/loss of 75,559 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Law rune  50  Common  15,450  
Chaos rune  50  Common  4,150  
Cosmic rune  50  Common  12,950  
Death rune  50  Common  7,200  
Nature rune  50  Common  22,000  
Body rune  200  Common  6,400  
Mind rune  200  Common  3,600  
Earth rune  200  Common  4,000  
Air rune  200  Common  7,000  
Water rune  200  Common  5,000  
Fire rune  200  Common  15,400 
Possibility 5  Iron oreEdit
The expected value of Possibility 5 is 53,101, which is a profit/loss of 12,609 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Iron ore  200 (noted)  Common  40,200 
Possibility 6  CoalEdit
The expected value of Possibility 6 is 34,201, which is a profit/loss of 6,291 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Coal  150 (noted)  Common  21,300 
Possibility 7  Rune barsEdit
The expected value of Possibility 7 is 54,271, which is a profit/loss of 13,779 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune bar  3  Common  41,370 
Possibility 8  GemsEdit
The expected value of Possibility 8 is 31,840, which is a profit/loss of 8,652 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Uncut diamond  3  Common  12,222  
Uncut ruby  3  Common  6,717 
Possibility 9  Loop half of a keyEdit
The expected value of Possibility 9 is 46,716, which is a profit/loss of 6,224 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Loop half of a key  1  Common  18,815  
Coins  15,000  Common  15,000 
Possibility 10  Tooth half of a keyEdit
The expected value of Possibility 10 is 50,689, which is a profit/loss of 10,197 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Tooth half of a key  1  Common  22,788  
Coins  15,000  Common  15,000 
Possibility 11  Rune platebodyEdit
The expected value of Possibility 11 is 50,510, which is a profit/loss of 10,018 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune platebody  1  Common  37,609 
Possibility 12  Rune platelegs or plateskirtEdit
The expected value of Possibility 12 is 49,946 for male characters and 49,792 for female characters, which is a profit/loss of 9,454 for male characters and 9,300 for female characters, if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune platelegs  1  Common^{[1]}  37,045  
Rune plateskirt  1  Common^{[1]}  36,891 
 ^ ^{a} ^{b} With Possibility 12, you are guaranteed to get either a rune platelegs or rune plateskirt. Male characters will always receive a rune platelegs, while female characters will always receive a rune plateskirt.
Possibility 13  Dragonstone armourEdit
The expected value of Possibility 13 is 6,030,579, which is a profit/loss of 5,990,087 if buying the crystal key on the GE.
 Receiving this possibility is very rare, at a rate of 1/6801.^{[1]}
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Dragonstone helm  1  Very rare^{[2]}  4,756,480  
Dragonstone hauberk  1  Very rare^{[2]}  11,204,522  
Dragonstone greaves  1  Very rare^{[2]}  5,336,736  
Dragonstone gauntlets  1  Very rare^{[2]}  4,368,708  
Dragonstone boots  1  Very rare^{[2]}  4,421,943 
 ^ https://twitter.com/JagexTimbo/status/557600452150579200
 ^ ^{a} ^{b} ^{c} ^{d} ^{e} With Possibility 13, you are guaranteed to get exactly one piece of dragonstone armour. Each piece has the same probability of being received.
Prifddinas chestEdit
This chest was released with the first part of Prifddinas on 22 September 2014, and is located in the Iorwerth Manor against the south wall. It has an improved drop table over the chest in Taverley. At the least, the player should still wear a Ring of wealth when opening either crystal chest.
Possibility 1  Tree seedsEdit
The expected value of Possibility 1 is 80,569.8, which is a profit/loss of 40,077.8 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Yew seed  1  Common  42,340  
Papaya tree seed  1  Common  50,312  
Elder seed  1  Uncommon  153,040 
Possibility 2  Herb seedsEdit
The expected value of Possibility 2 is 16,297, which is a profit/loss of 24,195 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Dwarf weed seed  1  Common  540  
Torstol seed  2  Common  2,856 
Possibility 3Edit
The expected value of Possibility 3 is 30,276, which is a profit/loss of 10,216 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Grimy lantadyme  5  Common  17,375  
Crystal tree blossom  1  Common  Not sold 
Possibility 4  TalismansEdit
The expected value of Possibility 4 is 34,109, which is a profit/loss of 6,383 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Fire talisman  5 (noted)  Common  7,660  
Water talisman  2 (noted)  Common  13,548 
Possibility 5  Rune HalberdEdit
The expected value of Possibility 5 is 88,342, which is a profit/loss of 47,850 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune halberd  1  Common  75,441 
Possibility 6  OresEdit
The expected value of Possibility 6 is 36,931, which is a profit/loss of 3,561 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Coal  80 (noted)  Common  11,360  
Adamantite ore  10 (noted)  Common  12,670  
Corrupted ore  50  Common  Not sold 
Possibility 7  Rune barsEdit
The expected value of Possibility 7 is 54,271, which is a profit/loss of 13,779 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune bar  3  Common  41,370 
Possibility 8  Uncut gemsEdit
The expected value of Possibility 8 is 31,840, which is a profit/loss of 8,652 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Uncut diamond  3  Common  12,222  
Uncut ruby  3  Common  6,717 
Possibility 9  Loop half of a keyEdit
The expected value of Possibility 9 is 31,716, which is a profit/loss of 8,776 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Loop half of a key  1  Common  18,815  
Crystal motherlode shard  10  Common  Not sold 
Possibility 10  Tooth half of a keyEdit
The expected value of Possibility 10 is 35,689, which is a profit/loss of 4,803 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Tooth half of a key  1  Common  22,788  
Crystal motherlode shard  10  Common  Not sold 
Possibility 11  Rune armourEdit
The expected value of Possibility 11 is 63,679, which is a profit/loss of 23,187 if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune full helm  1  Common  19,659  
Rune kiteshield  1  Common  31,119 
Possibility 12  Rune platelegs or plateskirtEdit
The expected value of Possibility 12 is 49,946 for male characters and 49,792 for female characters, which is a profit/loss of 9,454 for male characters and 9,300 for female characters, if buying the crystal key on the GE.
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Rune platelegs  1  Common^{[1]}  37,045  
Rune plateskirt  1  Common^{[1]}  36,891 
 ^ ^{a} ^{b} With Possibility 12, you are guaranteed to get either a rune platelegs or rune plateskirt. Male characters will always receive a rune platelegs, while female characters will always receive a rune plateskirt.
Possibility 13  Dragonstone armourEdit
The expected value of Possibility 13 is 6,030,579, which is a profit/loss of 5,990,087 if buying the crystal key on the GE.
 Receiving this possibility is very rare, at a rate of 1/6801.^{[1]}
Item  Quantity  Rarity  GE price  

Uncut dragonstone  1  Always  12,901  
Dragonstone helm  1  Very rare^{[2]}  4,756,480  
Dragonstone hauberk  1  Very rare^{[2]}  11,204,522  
Dragonstone greaves  1  Very rare^{[2]}  5,336,736  
Dragonstone gauntlets  1  Very rare^{[2]}  4,368,708  
Dragonstone boots  1  Very rare^{[2]}  4,421,943 
 ^ https://twitter.com/JagexTimbo/status/557600452150579200
 ^ ^{a} ^{b} ^{c} ^{d} ^{e} With Possibility 13, you are guaranteed to get exactly one piece of dragonstone armour. Each piece has the same probability of being received.
ProbabilitiesEdit
Taverley chestEdit
 The probabilities in this section are an estimation based on the data of 1000 crystal chest loots on the Taverley chest, while wearing a luck of the dwarves.
Possibility  Percentage 

Possibility 1: Fruit tree seed  6.4%^{[notes 1]} 
Possibility 2: Lantadyme seeds  7.9% 
Possibility 3: Grimy torstols  9.4% 
Possibility 4: Runes  10% 
Possibility 5: Iron ore  9.1% 
Possibility 6: Coal  9.8% 
Possibility 7: Rune bars  9.4% 
Possibility 8: Gems  8.3% 
Possibility 9: Loop half of a key  7.4% 
Possibility 10: Tooth half of a key  6.8% 
Possibility 11: Rune platebody  7.2% 
Possibility 12: Rune platelegs or plateskirt  8.3% 
Possibility 13: Dragonstone armour  < 0.01% 
 ^ The official RuneScape wiki lists the probability of receiving a calquat or papaya tree seed at 5:11 (45.45%) each and the probability of receiving a palm tree seed at 1:11 (9%). This data shows a probability of 48.45% for the calquat, 42.18% for the papaya, and 9.37% for the palm tree seed.
Using these probabilities, the expected average profit/loss, per crystal key, when looting the crystal chest is 8,298. Assuming you will receive whichever of the rune platelegs and rune plateskirt is worth more, and the crystal key is bought at GE price. This is excluding the possibility of receiving a dragonstone armour piece, as this possibility is much too rare to estimate with any acceptable accuracy.
Prifddinas chestEdit
 The probabilities in this section are an estimation based on the data of 20,000 loots of the Prifddinas crystal chest, while wearing luck of the dwarves. The loot from the Prifddinas chest is not affected by the Voice of Seren.^{[1]}
Possibility  Percentage 

Possibility 1: Tree seeds  7.59% 
Possibility 2: Herb seeds  7.555% 
Possibility 3: Grimy lantadymes  4.47% 
Possibility 4: Talismans  7.545% 
Possibility 5: Rune Halberd  6.00% 
Possibility 6: Ores  10.36% 
Possibility 7: Rune bars  9.455% 
Possibility 8: Gems  9.525% 
Possibility 9: Loop half of a key  9.30% 
Possibility 10: Tooth half of a key  9.045% 
Possibility 11: Rune full helm and rune kiteshield  8.81% 
Possibility 12: Rune platelegs or plateskirt  10.34% 
Possibility 13: Dragonstone armour  < 0.01% 
Using these probabilities, the expected average profit/loss, per crystal key, when looting the crystal chest is 5,024. Assuming you will receive rune platelegs, the crystal key is bought at GE price and the luck of the dwarves ring is worn. This is excluding the possibility of receiving a dragonstone armour piece, as this possibility is much too rare to estimate with any acceptable accuracy.
Estimate probabilities for nonguaranteed loot are:
 17.785% chance of crystal motherlode shard when rolling possibility 9 or 10. This assumes that possibility 9 and 10 yield the same chance for crystal motherlode shards.
 8.675% chance of recieving elder seed when rolling possibility 1.
 63.385% chance of recieving papaya tree seed when rolling possibility 1.
 27.94% chance of recieving yew seed when rolling possibility 1.
 20.39% chance of recieving dwarf weed seed when rolling possibility 2.
 79.61% chance of recieving torstol seed when rolling possibility 2.
TriviaEdit
 The crystal key chest was reworked on 11 June 2013 with the release of the Triskelion Treasures. Previous old drops, such as receiving 2,000 coins and a Spinach roll along with an Uncut dragonstone, were removed, and new ones were added, such as the Dragonstone armour.
ReferencesEdit
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