|Release date||11 March 2008 (Update)|
|Quest item||Kennith's Concerns|
|High alch||0 coins|
|Low alch||0 coins|
|Destroy||Rubium is very unstable - if you drop it, it will disintegrate. Are you sure you want to do this?|
|Store price||Not sold|
|Examine||Be careful with this near water.|
Rubium has high reactivity with water. Thus, during the quest, it is used on the steamers to raise the room temperature significantly in order to disrupt the workers. However, the rubium will burn up if players get kicked out, so they still need to be careful not to get caught. After the quest, players may sell rubium to Ezekial Lovecraft in his fishing shop, based in Witchaven for 10 coins per ore. Selling this will also update players' Ardougne Tasks. Players may also mix it into a guam potion (unf) at 31 Herblore to make a Super Fishing Explosive. Super Fishing Explosives give 55 experience to make and will generate 150 life points of damage to Mogres whilst luring. During Salt in the Wound, Ezekial utilizes homemade Rubium grenades as his primary weapon.
In total, there are only twelve rubium veins located in the mine, requiring 46 Mining to be mined and yielding 17.5 experience points for each successful dig. This is not generous experience, as it is only the same experience as mining the low-level ores copper, tin and blurite, thus making it useless unless attracting mogres. It cannot be mined with the Dwarven Army Axe.
Rubium will respawn when a player leaves and reenters the mine room.
- Rubium may be based on the real-life metallic element rubidium, which is also highly reactive with water and chemically unstable. Although rubidium is a silvery-white Group I alkali metal, it burns with a reddish-violet colour in a flame. In contrast, rubium is directly coloured as red. However, its reactivity more so matches Sodium.
- Despite its high reactivity with water, using it on any water source (sink, well, etc.) or any container of water (bowl of water, bucket of water, etc.) only yields this message: "Nothing interesting happens."