Fibonacci spiral, necklace in silver 925 with a layer of 24 carat gold.

Fibonacci numbers are numbers where each number is the sum of the two previous Fibonacci numbers; 0, 1, 1, 2, 3, 5, 8, 13, 21, 34…

A Fibonacci spiral starts with a rectangle partitioned into 2 squares. In each step, a square the length of the rectangle’s longest side is added to the rectangle. The spiral can be approximated by a sequence of quartz circles, one in each square.