Granulation is a jewellery manufacturing technique whereby a surface is covered in granules of precious metal.
There are three basic techniques that may be used to attach granules to a metal surface: hard soldering, fusing and colloidal soldering. The metals used in granulation are usually gold and/or silver alloys of high purity.
With each technique the process begins with the making of the granules themselves. The granules are usually made from the same material as the base to which they will be affixed.
Hard soldering- soldering metal items together, extremely small pieces of solder are positioned close to the point of contact between the granule and the metal and then heated to melting point.
Fusing- joins metals composed of the same alloy by the use of heat alone, the granules are positioned using a diluted flux and fine brush, at melting temperature the granules and sheet metal fuse, leaving no flux or solder.
Colloidal soldering- a colloidal mixture of tragacanth gum and copper salts. The mixture lowers the melting points of both granules and base, and causes the copper to diffuse into both at the point of contact, creating a strong metallic bond.
A variety of the jewellers we work with use granulation in their jewellery. A few examples below.
A beautiful deep green tourmaline ring with white diamonds and granules of yellow gold, on a lightly textured band, made by Ruth Tomlinson
Oxidised silver circle earrings encrusted with 18ct gold clusters made by Hannah Bedford
White gold ring, Three contrasting cuts of white diamond fit together to form a striking and elegant engagement ring by Ruth Tomlinson with plenty of sparkle, in white gold.
We have a greater selection of jewellery with granulation in our Exeter and Taunton stores.