Completing the Daily Guild Wars 2 Achievement earns some experience, coin, a chance at a black lion consumable, and a single Mystic Coin.
The monthly achievement gives more of the same, including a lump sum of 20 coins.
The tool tip implies that this can be used at the Mystic Forge in Lion's Arch, but doesn't say much more than that.
What combinations are the coins required for? I'm not looking for every recipe, but non-random recipes should have a "standard mixture", much like how crafting basic arms and armor is, for example, Metal Chest Panel + Cloth Chest Padding + Insignia = new Chestpiece
.
I've heard that these coins can be used to receive crafting recipes, and also high-level weapons – what's the skinny there?
Best Answer
Take a look at the Wiki on the page Mystic Forge. It will tell you where the forge is, how it is used, and some predictable recipes. The forge lets you do two things. First you can create recipes to craft other items like consumables, weapons, or armor. Second, the forge can be used to create better crafting materials of one type higher.
The examples the wiki gives are as follows:
In that example: That recipe will produce 10-50 Orichalcum Ores
Mystic coins seem to be a common item needed for Food Trays, Weapons and Armor. Also look at this page for current recipe research.
You can see this in action with this video on how to make a Giant Chocolate Cake. Details are in the video summary.