the delightful numerology necklace is set in 18kt yellow gold and adorned with white sapphires. to find your special numerology you will need to add your date of birth for the date, month and year separately till you achieve a single digit.for example if you are born on the 7th of july 1983 your numerology calculation is as follows 0 7=7 (date), 0 7=7 (month) and 1 9 8 3=21==> 2 1=3 (year). you will need to add 7 7 3=17==> 1 7= 8.the necklace is hallmarked by the london assay office.