Stalactites are stones hanging from the ceiling of a cave - formed by water running down from the ceiling and taking little drops with material with it. Formed over years they are growing and looking like icicles made of stone. The water dropping down on the floor of the ceiling are named stalagmites, by the way.
There are no such things as "stalacites".
sedimentary
stalactite forms form the top stalagmite forms the bottom
Conglomerates.