This style of bead is generally called a "gravity" bead as you allow gravity some leeway to drag the design down before righting the bead to restore its symmetry. I was fossil hunting in Whitby with some success and it was the little ammonites that made me think of trying this out. I'm calling them my Inspirals and I've got at least 3 colour combos so far.
I particularly love the orange and yellow variety above as they show up the effect really well. There is only one question...do I try out a new style now or just carry on with more and more colours !!