The two "main" magical ores I see are mythril and adamantine, which are great, but fail to hold up to the variety of magic in d&d. There are some ores I have seen around on different wikis and such from the older editions, but I am hungry for more! What are some magical materials that you have seen in older editions or have used in your campaigns? I'm not just talking about metals, mind you. Crystals, gemstones, special wood types, even the hide or bones of magical beasts. You could even find ways to make real life materials magical. If silver damages fey and werewolves, what could gold do? Go crazy, fellow DMs, and write it below so that we can collectively steal from each other. 

Everslate: harvested from the remnants of dead gods in the astral plane, Everslate is a strange grayish green metal. Everslate cannot be destroyed, but it can be changed. Once it is smithed into an item or weapon, it is indestructible by any means short of a god and cannot be transfigured by any known method.

Soarwood: a type of tree known for being able to levitate chunks of earth it is rooted to. Weapons made of soarwood weigh one quarter their normal weight.

Dead man’s teeth: dead man’s teeth, also called Mortestone, is a type of rare crystal that glows bright blue in the presence of a dying creature. It got its name for its tendency to grow in the skulls of humanoid corpses, especially on teeth. It is often used to fashion weapons such as daggers, which can tell people if a strike they land is a lethal blow or not.

Aberrantite: A type of stone that has, over a long period of time, been exposed to the alien energies of the Far Realm. When incorporated into a weapon or magical item capable of inflicting damage it deals additional psychic damage. But can also gives the wielder terrible nightmares, encourage erratic behaviour and even, with long exposure, cause physical changes.

Orichalcum, was supposed to be a magical metal in Ancient Greece and Atlantis.

dragon scales. inflicts an extra amount of the dragons damage type, but also induces hoarding mentality

lithostone. a kind of stone with simple figures painted on it, causes devolution in either the attuner or the target

bloodsteel. a kind of steel forged with a specific creature's blood. any weapon made of this has a higher chance of hitting a target of the same species the blood was

Technically speaking adamantine and mithral aren’t “magical” materials in this edition. They’re rare and special but not actually magical. The designers decided to move away from inherently magical materials for this edition. Adamantine and mithral armors are magic items not because the materials themselves are magical but because they have also been enchanted. That’s why adamantine armor is magic but adamantine weapons and ammo aren’t. If you read the rules for making magic items in either the DMG or XGtE it talks about needing a recipe and one or more special ingredients. I don’t remember which book it’s in. The special ingredients for those armors are those metals just like dragon scales or hide would be the special ingredient for dragon scale mail. That’s why there’s no green or red steel this edition. That’s why you can’t really find much of anything either. They just don’t exist in this edition like they did in older editions.

Some special materials from adventures

• Gulthias wood comes from an evil vampiric tree and magic items from it have the ability to drain life force from others or inflict madness gulthias staff. It can also be used to make wooden constructs
• Chardalyn is demonic ice that is as strong as steel. Weapons made of chardalyn are toxic inflicting poison on people and can drive people insane. The materials also has it's own demonic will making it easy to make constructs from but making those constructs act demonically.

Some home brew materials are 

• Alexandrite a real world colour changing gem stone. I use it as a material that can switch its elemental affinities between two or more types allowing for multiple elemental enchantments that it can switch between.  I also use it for for magic items with prismatic effects such as a sword which can cast absorb elements.
• Amber which can easily generate static electricity. In fact it's ancient greek name Elektron is actually where we get the word electricity. Magic items made of amber tend to have electrical effects. 
• Obsidian or volcano glass in the real world is highly heat resistant can be used to make very sharp tools.  I make it so it's good for making slashing weapons, can't be destroyed by fire and ignores the resistances of/ triggers the weaknesses of fire elementals. Stuff like making a shield of fire resistance that also does slashing damage on a bash is on the table 

As for gold, in alchemy its associated with purity, holiness and the sun.  The obvious answer would be silver for werewolves as silver is connected to the moon and gold for vampires because its connected to the sun.  Though in allot of media gold is often treated as a particularly magically compatible material with orichalcum being a gold like substance that's actually useful for making armor and weapons. In the story of atlantis orichalcum has the properties of both gold and copper but in 3.5  and pathfinder is has a bonus to enchanting.

Residuum was a pretty good catch-all byproduct used during the 4th-ed era to quantify magic used in item construction. It tended to be found in powdered form and was basically the physical manifestation of magic enchantment. Generally a byproduct of breaking down a magic item, it could be used in the enchanting rituals for making new magic items.

Upsidaisium- an anti-gravity metal

Unobtainium- A substance with the exact properties needed for a piece of hardware or other item of use, but not obtainable, either because it theoretically cannot exist, or because geopolitical events preclude access to it, or because current technological limitations prevent making it. 

More here - https://en.wikipedia.org/wiki/List_of_fictional_elements,_materials,_isotopes_and_subatomic_particles

If we’re just supposed to make stuff up or talk about stuff we already made up then shouldn’t this be in the homebrew forum instead?