All gold formed at the primary level (reef born) has a crystalline structure, however distinct valuable crystals always show well-formed faces, and they are relatively rare.
They require special conditions to form, in particular space in which to grow.
Most crystals of gold are found in the cavities of quartz reefs and also in softer minerals such as iron oxides where they have been able to push aside the enclosing material as they grew.
Gold crystallizes in the cubic system, and perhaps the most common variety is the eight-sided octahedron.
Your sample most certainly looks to be crystalline bushpig as I can see small pieces of ironstone in the structure which would more than likely point to Primary gold.
Having said this, the faces are not well formed and its not of a pure 'cubic' nature so it would not be considered very rare.
But you know what?....its still gold and a very nice piece mate.