Being probably the most rare type of crystal in the game, supply is almost always rather low on these crystals.
Now, with the increase in demand for them, due to more and more people crafting with them (namely Padded Caps ^^ ), the price has been skyrocketing lately.
I went to Rabao today, to join my fellow fisherman/crafters [ quite a few are bots, might I add ;) - tell-tale sign, they fish there 24 hours a day, EVERY DAY ], and seeing as it had been a while since my last fishing/crafting expedition, I had no light crystals in my safe. So I run over the the Auction House, and lo and behold, Light Crystals are up to 10k a stack. This from just about a week ago, when they were 6-7k a stack. Clusters, same story, but sold out. Only 6 stacks available. I picked up 2 stacks, as I didn't have the chunk of change to spend on all 6 at the time. About 1/2 stack worth of synthesized caps covers that cost, leaving another ~43k profit to come from the remaining 18 crystals. But, of course, the non-tangible cost of many hours spent, intentionally fishing up items.
Almost makes me wish I had the morals to use a fishing bot. So instead, I sit there, logged in for a few hours, while doing stuff away from the game, letting the anti-bot code raise my percentage of items caught... hoping that I can blow through these last 18 crystals in only a couple hours when I get back.
I guess the point to my post, those of you who can farm Light Elementals, please do so... we need more crystals. Hopefully something changes soon, and the supply curve shifts again. I rather liked the 50k profit from 2 stacks of crystals far better than 43k.
It's too bad SE nerfed this.. It was a great way to make money. At least it lowered the price of Light Crystals at the AH. Not as much of a demand anymore.
You can use grain or herb on darksday with dark crystal and they will yeild. I think the two best pots are earth and ceramic, if you use brass there is a better chance of it being a black rock. (Not sure on that though.. gonna test in two weeks.) I need about 12 stacks of light crystals so I am growing them. You should check out pikko's website http://www.swapsonian.com/pikko/index.html taught me almost everything I know.
Not accurate, you can get 11-70 crystals using a Porcelain Pot. But you are correct about the elemental aspects of this, I.E. water = fire.
Also, if you want more crystals when you harvest, rather than normal items, you feed the plant the crystal on a day that is opposite of the crystal... I.E. Feed a Dark Crystal to your plant on Lightsday to get Light Crystals. I think that would be right o_O??
After killing cardians alot today the Coin Cardians drop light crystals.. i found maybe 5 or 6 all day.. although the coin variety don't have the most populous in the ruins in East and West Saru they still drop them.
Out of boredom and leveling SAM a bit on EP mobs, I got 2 in 3 hours... 2. I got a stack of wind, earth, and 3-4 fire, and 2 whole light. :) Only the coins dropped them.