To obtain the Magma Vein, you have to ask around Tzhaar before a random NPC will reveal where to locate it. They will say the Magma Vein is found only in the deepest sanctum of Tzhaar. Find one of those Guard Tzhaars and Speak with them. Mention the Magma Vein and they will allow you in... under one condition.If you want to know more about RS, you can visit https://www.rsgoldfast.com/