The opal machete is a members only machete which cuts at a faster rate than a normal machete.
The opal machete can be obtained either from Gabooty's store with 500 trading sticks, trading with another player, looting a ninja impling, or bringing materials to Safta Doc in Tai Bwo Wannai village. The opal machete can be used as a weapon but is primarily used to cut jungle during the Tai Bwo Wannai Cleanupminigame. It has no requirements to wield though cutting light, medium, and dense jungle requires 10, 20, and 35 Woodcutting to harvest respectively. A machete can be used to cut the roots of evil trees (effectiveness unknown).
To make an opal machete bring 300 trading sticks, 3 uncut or cut opals, and 1 gout tuber to Safta Doc in Tai Bwo Wannai village. However, the cheaper/faster option to obtain the machete would be to buy one from Gabooty's store or the Grand Exchange; this is because gout tubers are a rare find from playing the Tai Bwo Wannai Cleanup minigame, and the machetes are currently very cheap on the Grand Exchange. The opal machete can be added to the Tool belt.
Getting Safta Doc to create an opal machete will count towards the That's Not A Knife... task in the Karamja Tasks.
Gout tubers are worth far more than the resultant opal machete. Therefore, it makes no sense to get one from Safta Doc except for the diary. Players should make sure to start the diary before having Safta Doc make the machete or they will have wasted their gout tuber.
At one time, when participating in the Evil TreeDistraction and Diversion, a player would automatically use a machete instead of a wielded hatchet when cutting down evil roots.