William, you don’t need any white gold between the stones. The
purpose of putting four princess cuts together is to give it the
illusion of being one big stone. As long as the four seats are cut
right; so that the stones girdles are touching each other, the bezel
around the four diamonds will hold it in place. The outside bezel
pressure seems to make the diamonds “bite” into each other and hold
it in place. Have been doing this with diamonds, making
rings,pendants and ear rings, for over 25 years and had no complain.
Wouldn’t try it with any other type of stones. Since I work only in
wax; what I do is to place a two-way or two-face transparent tape
onto a graph paper and align the four stones face down with space the
thickness of a paper between them (this is to compensate for the
casting shrinkage). The graph paper is only a little larger than the
four stones and is taped down to prevent it from moving and buckling
when I pour the hot wax onto the pavilions. This way I get the four
seats made at one stroke as one complete base. Min Azama in Tokyo.