Good Question word is Miners where finding it in trammel caves i dont know if this is true
but so far the only place i seen it happen is the Black Rock Crystals the Elementals and such are guarding...

Just to maybe help out with the Blackrock mysteries

I have a miner, I am on the Lake Supieror shard, I been mining all day in Trammel in various locations from a Runebook and in about 4 hours time I have mined up 27 pieces of Blackrock. They are the small pieces, but non the less I have still mined them up in Trammel. I would not say that your chances of mining them up are low as I have said before 27 in 4 hours is not a bad find.

Hope this helps everyone. I have a question though... What are they used for or what can they be used for?

Thanks
Cy

its still unknown

There is a Wisp that is summoned on occasion, though we are still trying to figure out what tome of suficient size it is looking for. People are also hearing strange voices after casting the spell.

I know not the spell which you are talking of, however, my first time out and less than 50 swings of my sturdy pickaxe I have acquired 3 large pieces of blackrock

Dang It!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I been mining for two days in trammel and in nasty land (Fel). and have not yet got 1 black rock of any size. This is going through half dozon or so sturdy picks and many tinker shovels. Oh well maybe its waiting for me to mine the biggest black rock ever to be found.

You need to mine in one of the three special locations -- the blackrock crystal spires-- to get the large chunks of blackrock. Right near the base of them. The easiest one to mine is the one just west of the Ophidian Lair--more open space there for dodging the guardians. BUT you will need to hide or invis. A stealth miner works best.

When I went to lost lands mining for blackrock, I was near the spires and the uses on my trusty pick axe were not depleted at all and I was able to get 1 large (25 stones) and 2 small (7 & 12 stones).... I did this while hiding and there were 3 blackrock elementals, a vortex and the slime thingy... hahaha what a rush!! teehee