Tiberium

Tiberium is a gem present once The Sims 3: World Adventures is installed.

About Tiberium
Tiberium is a very rare and often valuable gem. The ore itself is around §100, and getting it cut greatly increases the value of the gem. Whether it is a raw ore or cut, it will give a Sim a negative moodlet (-25 mood), so it is best kept out of a Sim's inventory. No matter what its form, it will glow and make a soft "ping" when placed on lots.

Getting Tiberium

 * Buy it from relic stores, most likely from Egypt.
 * Break Space Rocks with a Board Breaker. Requires Level 9 of Martial Arts skill (7 for Disciplined Sims) and that the said sim has completed the Timber Terminator Challenge.
 * Exploring the mausoleum in the cemeteries.
 * Use the Miner (present in The Sims 3: Ambitions) to find it.
 * Put an assortment of gems and other objects on a Display Rack, making sure the price of ALL items combined makes §3500-5000, then perform the Irreversible Transfiguration. Doing so will give a small spire.
 * Search neighborhood garbage cans
 * Dogs can dig up Tiberium in TS3 Pets expansion.
 * Using the debug cheat, go to the gem/metal spawners and click on one of the Tiberium spawners. Although such spawners will also create other far less valuable gems, such spawners should reliably spawn tiberium given enough time (and stack)

Cuts
Tiberium can be cut into 2 different forms: No matter what the cut is, (whether it's heart, small spire, or raw) Tiberium outside Sim's inventory will grow into a Large Spire Cut within a day, giving it a value of around §40,000. With Supernatural installed, even the powder will grow into a Large Spire cut if processed through the Gem cutter. Henceforth the Gem cutter is a great way to double the profit.
 * Small Spire Cut (§6500)
 * Heart-Shaped Cut (§1000)

Spreading
The claim that Tiberium can spread propagated early on after its introduction into Sims 3 in hopes that it would mimic its behavior in the Command & Conquer universe. This, unfortunately, has been disproven by many threads such as this on the official Sims 3 Forums.

Trivia

 * Tiberium is present in the Command & Conquer series as a fictional substance that is central to much of the plot of the story. The series was made by Westwood Studios and later acquired by EA.
 * Tiberium is one of the most valuable materials available that is associated with a spawner (namewise) that is placeable via BuyDebug, alongside Supernovium, Compendium, Mummitomium, Plutonium, Opal, and Soulpeace. Tiberium spawners will also spawn Luminorious Gems alongside other less valuable gems, most notably amethyst.