The Treasure Trails Clue
Treasure Trails are one of "RuneScape's" Distractions and Diversions features. Every so often, a nonplayer character, or NPC, or a monster will drop a scroll with a clue on it.The clue to the sapphire is in the form of a riddle: "46 is my number. My body is burnt orange colour [sic] and crawls with those with eight. 3 mouths I have yet I can not eat. My blinking blue eye hides my grave." Forty-six tells you the Wilderness level; burnt orange is the color of the location on the map; and "those with eight" are spiders. The blue eye is the sapphire and the "grave" is the place where you must dig.
Equipment
You need to dig to obtain the sapphire so you must bring a spade with you to the spider nest. Since you will almost certainly be facing combat, you should bring food to restore your health. You may also find prayer potions useful.
The Wilderness
The level of the Wilderness tells you how high or low the combat levels of your opponents will be. In level-46 Wilderness, the combat levels are your combat level plus or minus 46. The Wilderness is the most dangerous area in the game. There are many monsters and you may find yourself fighting other players. If you die in the Wilderness you will lose your items. Don't bring anything you are not prepared to lose when you go looking for the sapphire.
The Spiders' Nest
The "nest" is actually a hill. It is crawling with brown spiders. These will generally not attack you -- until you take the sapphire, after which the spiders will turn on you en masse. As well as the spiders, you must beware of player killers in this location as it is in a player-versus-player area.
The Sapphire
The sapphire itself is at the top of the hill where the spiders have made their nest. You must dig beneath the sapphire with your spade to obtain it. The sapphire is a respawning resource, meaning that f you remove one, another will eventually respawn to take its place. This takes some time; the spiders' nest sapphire is one of the slower-spawning resources in the game.