Stone 34 is possibly the most elegant example of a lozenge shaped monolith in all of Avebury.   Professor Meaden, on page 4 of his "The Secrets Of The Avebury Stones" explains the particular significance of the triangle and the lozenge during the neolithic "... the triangle ... sympolises the vulva and pubic zone by which it stands for the Great Mother as the source of all life.   At the same time it is the sign of the original trinity - the triple goddess in her three ages of maiden, mother and wise woman.   The lozenge symbol goes farther, for it is made up of two triangles base to base, in which the upward pointing triangle can indicate the navel triangle ..."   On page 59 he notes that the heart-shape in the center of  Stone 34 is probably natural, and he states that the mark here "may have been given a symbolic significance in the spirit of the times" - I suggest that to the neolithic mind the mark might have been seen as a distended vulva at the moment of birth, or (as the Avebury religion was concerned with reincarnation) a circle of life motif.  It seems to me that such interpretations might be supported by noting that the carving of the stone's lozenge perimeter shape has been done to deliberately place the heart at the very center of this most feminine monolith - the stone's configuration is far from accidental, a feminine lozenge with a feminine heart.

A Bolder Explanation

Stone 34 here may well be a highly stylized example of what I have called a "dual symbol" stone,  below is an animation comparing our Stone 34 on the right with a strikingly similar example of a dual symbol in the Avenue, the correlation between these two monoliths is shockingly precise: