How do you get 13 orchalum plus?

Answer 1

1. When in Twilight Town as Sora,one teasure chest In Sunset Terrace.
2. Complete the Goddess of Fate tournament in the Underworld.
3. In The World That Never Was, in The Brink of Despair, on the left there's a skinny ledge against the side of a building. There's a treasure chest holding an Orichalcum +
4. Complete the Atlantica side-quest.
5. Complete the Hundred Acre wood side-quest.
6. In Space Paranoids during the second visit, when you get off the Solar Sailer there's an area with 4 treasure chests. One of them holds an Orichalcum +
7. Gather one of each synthesis material You just need 7,use a energy stone to cut materials in half (:.sorry about my bad English,I'm Brazilian and only 15 years old (: