How to Get a Sapphire in FireRed

Navigate your way through the trainers situated within the island. Head east to the island's edge to approach a path where a hiker stands. Fight your way through the path of grass and turn left at the upcoming intersection. Turn right at the next intersection, heading up the cliff ahead.

Walk north, and then east to approach two explorers; go south once you reach another. Head left and continue north until you reach a strange-looking temple. Walk up to the door and use the HM "Cut." Walk forward and fall through the hole once the door opens; you'll land in another room with four other holes.

Fall through the topmost hole and continue through the left hole on the next floor. Enter the right hole and then the bottom hole to complete the sequence. Approach the Sapphire and watch the Rocket scientist take the Sapphire from its shrine. Exit the shrine room to follow the Rocket scientist.

Head to Island Five, or Chrono Island, to the Rocket Warehouse. Follow the left-facing arrows once you're inside. Walk one space left to the top left side of the room, heading right after you reach two side-by-side arrows. Take another space left onto a yellow square, and head toward the Rocket member.

Walk left, following the arrow near the Rocket member two spaces away. Go forward until you're standing to the north of the Rocket member. Take either path from the arrows facing you, and battle the Rocket member at the end. Follow the next right arrow to reach the Rocket Executive ahead. Battle the next Rocket Executive near the computer, and head north after the battle. Talk to the computer-bound scientist to finally receive the Sapphire.