The back of silver mirror is usually coated with gray. And the aluminium mirror back is often coated with red. Certainly we could also distinguish the silver one and aluminium one by the front colors. Silver mirror is in dark ruby color, and the aluminium one is more white and bright.
The appearances of silver mirror and aluminium mirror looks the same. But material cost for making silver mirror is more higher than aluminium mirror. So the prices and texture are also in different. At first, silver mirror is made of silver electroplating composition, but the aluminium mirror is made of aluminium. On the other hand, the silver one is more expensive than aluminium one. Besides they are in different brightness. The performance of silver is better than aluminium mirror. With the same light intensity beam, the silver one looks more brighter.
Article From: http://www.hhglass.com/news/How-To-Distinguish-Silver-Mirror-And-Aluminium-Mirror.htm
