There is no special soul altar. From runescape.wikia.com: "The Ourania rune altar allows runecrafters to craft a random selection of runes, including the soul rune." So, if you go to the Ourania altar, you will craft random runes, including soul runes now and then.
Chat with our AI personalities
crafting runes at alters. Use runes ess at certain alter to craft those runes. Eg water alter you crft water runes.
earth or fire cause they are very close to banks
You can buy it at ge or you can do the quest calles rune mysteries so you can actually craft runes.
No.
A mind tiara is a mind talisman that you wear. If you do not know what a mind talisman is, Well than a mind tiara is used for making mind runes, it helps you find the mind runecrafting place and you need a mind tiara/talisman to craft mind runes!