Antique pink topaz and diamond graduated necklace

The 26 oval facetted pink topaz alternating 26 old European cut diamonds, open cut-down collet set, the topaz in yellow gold, the diamonds of approximately 6.50cts in silver and gold backed, the largest topaz approximately 4.70ct
Length 46cm / 18''

Central topaz approximately 14.0 x 10.0 x 4.7mm and of approximately 4.70ct
Weight: 37.5g