You will need transmute ___ reagent recipes and a Card crafting station. Transmute recipes can be found in Grizzleheim and in Celestia for certain. In Grizzleheim, the crafter is to the left side of the village main street, just before you go up to talk to the Bear King; in Celestia he's at the far right back of the Base Camp, right next to the door to the Survey Camp.
In almost all cases, it takes 15 of a commonly dropped reagent to make 1 of the rare ones.
For example, 15 ore = 1 diamond.
That said, it has been my experience that, by the time I gather all the ore I need to make 10 diamonds, I've also gathered 10 diamonds. So basically, I never actually use the transmute recipe. (But still, it's nice to have ... just in case.)
Some plants also drop diamonds when you harvest them, especially Fickle Pickles and Frozen Fly Traps.
You can craft reagents by "transmuting" them. Most reagents can be crafted by 15 of something (x). However, I believe you need access to the Floating Lands in Celestia, or just teleporting into the Water-mole village, and have Grandmaster Artisan. I bet you're Adept as of now, trying to get Master Artisan.
I was told that i could craft reagents. If this is true, how do i do it. I really need some diamonds so i can finish my crafting quest.
You can "transmute" reagents into other reagents, you just need the recipes and a Card craft table to do it. Visit the recipe vendors to find which one sells the transmute recipe you need ( look for the reagent icon on the tabs ). I believe Toshio in MooShu sells the recipe you need.
If you can get to Celestia, the treasure card recipe vendor in the main area there has a lot of transmute recipes. I found him easiest or fastest to get to. You go to Celestia and he's right in the main area. Some of the other worlds that sell those, you have to go and find the vendor.