I'm pretty sure a lot of people have figured out Mystic Forge recipes, but are just hording the information to make profit, so I'm trying to share what I know and aggregate info from the community. Right now coins are REALLY cheap (like 54 copper) because people don't realize how useful they are, so many are taking advantage of that. Mystic coins are actually very valuable, don't make the mistake of selling yours for cheap
So I bought a lot of singletons of crafting materials so I could see what recipes the Mystic Forge has. Here's what I found. Where I don't know the result, I just made up a silly placeholder name. Here's a list of shorthand I use (Miyani is the NPC next to the Mystic forge)
Wine = Elonian Wine - 25.6 Silver from Miyani.
Scroll = Eldritch Scroll - 50 skill points from Miyani
Crystal - 5 for 3 skill points from Miyani
C. Dust - Crystalline Dust
When I refer to fine crafting materials like bones, I mean the tier 6 version (e.g. Ancient Bones). Anything lower won't work, but you can transmute lower tiers up using philosopher stones.
Lodestone:
2 Core + 1 Crystal + 1 Wine + 1 C.Dust = Lodestone
For example, if you use two Molten Cores you will get 2 Molten Lodestones. This is useful because I'm pretty sure some of the Lodestones, like Crystal Lodestone, don't even drop from enemies since there are no high-level branded enemies
Mystic Weapon (level 80 exotics with particle effect):
1 scroll + 30 coins + 5 component A + 5 component B
For example, to make a sword you use 5 orichalcum hilts and 5 orichalcum blades. It only accepts level 80 components (so orichalcum components)
Gaze of Demon Summoning (level 80 focus - 64 pow 64 vit, 90 cond dmg, sup. sigil of demon summoning)
1 scroll + 40 coins + 5 crystals + 50 skulls
UNKNOWN RESULT RECIPES (with placeholder names):
Zommy's Mat
1 scroll + 30 coins + 30 crystals + 1 wine
Sylvari Exalted Cultural Armor Mach VI
1 scroll + 30 coins + 100 lemongrass + 100 spools of gossamer
Volcano Weapon
1 scroll + 50 coins + 50 destroyer cores + 50 molten lodestones
Bloodrazor
1 scroll + 50 coins + 250 powerful blood + 250 vicious claw
Eye of Sauron
1 scroll + 50 coins + 250 powerful blood + giant eye
Hellbringer
1 scroll + 70 coins + 100 bones + 30 molten lodestones
Ultramat
250 c. dust + 250 totems + 250 venom sacs + 250 bloods
Megamat
250 fangs + 250 scales + 250 claws + 250 bones
PARTIAL RECIPES OF MYSTERY:
Scroll + Ecto + Coins + ?
Scroll + Ecto + Crystal + ?
Scroll + Ecto + Philo Stone + ?
There are also probably recipes using the other lodestones, but I ran out of money and couldn't buy them to find out. Let's work together as a community and chart this unexplored territory! I'm pretty sure some of these recipes at least give you the exotic components for legendaries.
Just to emphasize, the names are placeholders because I don't know what the recipes actually make. If the reddit community can band together and chart new territory, then I think that would be awesome! To the best of my knowledge the results of these recipes isn't available publicly anywhere.