An excerpt from a post that originally appeared on http://caribbeannishikigoi.com/
Kin Gin Rin is abbreviated to "Gin Rin" by Koi hobbyist, breeders and sellers. It is literally means
Kin Gin Rin is abbreviated to "Gin Rin" by Koi hobbyist, breeders and sellers. It is literally means "golden silver reflective scales". Kin Gin Rin Koi was developed by Mr. Elizaburo Hoshino. It was 1929 when Mr. Hoshino came across a fisherman who had caught Magoi with many sparkling scales that catches his eyes. That fish was used in the development of Gin Rin.
Kin Gin Rin is not a variety of Koi. It is a reference to a Koi's scale. For example, on a red fish such as a Kohaku, when Gin Rin appears - it has a gold appearance that you can easily notice. Scales appear golden when they cover red pigment. On the other hand, the silver effect is due to the presence in the scale of a chromatophone. Scales appear silvery when covering white or black pigment. This sparkling effect is strongest on young Koi. However, the scales get thicker and will often fade away or sparkling effect becomes less visible as the Koi ages.
There are four types of Gin Rin scales. Diamond Gin Rin is the most common as appears like cracked glass or brushed aluminum over the entire scale. The second type is Kado Gin or known as Edge Gin. Each scale is edged in silver as exactly as it sounds. It is the most uncommon type and least preferred. While Beta Gin is hard to find and with highly valued type. It is shining like a mirror because the whole surface of the scale is being covered with silver. Pearl Gin Rin is the last type of Gin Rin scales and by far rarest of all. It seems that someone carefully mounted a diamond on each center of the scale, similar to pearl.
If you would like to search for a good Gin Rin Koi, a Koi should have two or more complete rows of scales from the shoulder and end at the tail. Remember to avoid those jumbled Gin Rin scales and just look for a neatly organized scale. It should be evenly lined up in rows and with consistent shine.
The Gin Rin Koi is flashy and glitzy that seem to be covered with diamonds. It is highly reflective and you will notice a brilliant enhancement that sparks when it catches the light. Your pond will surely shine by this so-called "Living Jewels."