Featured in this lot is this 4.28cts tanzanite diamond and platinum ring with GAL paperwork. The ring features a wonderfully and professionally crafted platinum construction that features a 'Sheffield & Sons' hallmark with a 'PT950' mark underneath the hallmark. The center stone is a emerald cut tanzanite gemstone that measures 10.37 x 7.70 x 6.13mm and shows violetish blue and is moderately strong saturation and is transparent with a total weight of 4.28cts. Tanzanite Is a very rare precious gemstone that is only found in the Usumburu Mountains that border the Umba Valley of northern Tanzania. Originally discovered in 1967 by Tiffany & Company who named the stone Tanzanite. Tanzantite is unique due to its exceptional pleochroism (an optical phenomenon in which a stone has different colors when observed at different angles). The pave set shoulders and center stone are profusely decorated with a total of 24 round brilliant cut diamonds that shows a clarity of VS-SI and a color gradient of F-G and a total weight of 0.47cts. The piece comes complete with GAL(Gemological Appraisal Laboratory of America, Inc., a GIA certified lab GAL Appraisal Number#: GAL202216774) report and appraisal confirming the above info and giving a total value of $12,900.00. The ring size is US 7.