Metals

Besides the vanilla resources, one can gather (such as iron, gold and diamonds), players can also obtain various additional Star Wars metals.

Grades

Metals are divided into different grades. Grade 1 is the most common grade, and this goes all the way up until Grade 5. which is the rarest grade. The higher the grade, how harder it is to obtain the metal. Higher grade metals don't necessarily offer better stats for armour and modifications.

Function

Most of the metals are necessary to forge armour or weapons with. However, some metals can be forged into modifications or enhancers, which boost a specific stat from the player. Most Bountyhunter armours require Beskar, and most Trooper armours require Quadranium.

Distribution

Most metals are tied to a specific planet, meaning they are only obtainable on specific a specific planet. Some metals, however, are only obtainable through crates, dungeons and quests, as the planets they should be tied to aren't on Star Wars Network yet.

Obtainability

These special metals can be obtained in various ways:

Mining iron ore
When mining iron ore on planets there is a very small chance that an additional metal will drop. Although this might be the easiest way to obtain these metals, it's most definitely the least profitable.
Dungeons
Armoured troops in dungeons have a chance of dropping metals. This is the fastest way to obtain metals, but also the hardest, as most dungeons with armoured troops are very hard to survive in. For more information about which specific metals certain dungeon mobs can drop, check out the dungeons page.
Crates
Opening crates is another way to obtain metals. Planetary crates have a chance of dropping the metals tied to the planet, and non-planetary crates (rare, legendary) have a chance of dropping metals which aren't tied to planets. Metal Crates only drop metals, but the chance of obtaining the right metal you want is quite slim, as all metals are droppable in that crate.
Quests
A few quests have metals as a reward, but these are simply bonus rewards and aren't recommended as a consistent income of metals.