How and where do double-terminated crystals form?

Question

How and where do double-terminated crystals form?Most terminated crystals form by 'growing' out of a rock. Which causes one side to be flat,(or whatever the shape of the rock it 'grew' out of was shaped like), and the other side to be 'terminated'. Meaning that the one side has a natural faceted end.Double-terminated crystals obviously couldn't form like this.

Answer 1

Crystals do not "grow" out of rocks. A crystal forms out of a hot liquid solution (be it magma or mineral-rich water) when it begins to cool (much like the sugar-crystals of rock-candy). As the solution cools, the elements within bond together to become more stable. This continues in a repeating pattern that forms a crystal.

Double terminated crystals are crystals that have formed within a solution and have exhausted the solution of the chemicals that make up that crystal, resulting in terminal ends on both sides. When a crystal has only one terminal end, that indicates that its growth either started on a surface that prevented it from forming another terminal end or was interrupted after one end had formed by a lack of growth space.