The Seven Islands are not in Pokémon Sapphire.
1 island 6 island
You don't on Island 6. You head to Island 5 and the rocket base where you will find him and the Sapphire.
find the sapphire for 7 (in a cave on 6 island, use cut on the brail door.) 8 and 9 idk about sorry.
you find the ruby in the cave right next to mount ember on island 1. to get the sapphire gem you have get the pass from celio to go to island 4567 and it is on island 6
Go to two island and go up keep going up and eventually you will find it the saphire.you get the Sapphire in the ice fall cave and you get the ruby in the dotted hole on 6 or 7 island
======================================================================================================================================== you can not go there it is only for fire red and leaf green
you get the ruby and the sapphire in 6 island and 1 island
the seventh gym in pokemon sapphire is in mossdeep city.
the ruby is in the cave near the entrance to mt. ember and the Sapphire is in a cave on 6 or 7 island where you need to use cut on a door that has brail written on it.
you have to go to ruin valley and use cut on the metal door and there is the sapphire
you go to the 7 is island
after you beat the elite four, go see celio in the Pokemon center on one island. he will ask you to help him get the ruby. (its in mt. ember) then, give him the ruby. he will also ask you to find the sapphire, which is on six island. then, he will give you the rainbow pass, which allows you to go to 4, 5, 6, and 7 island.