Unusual Victoria Jubilee Medal Commemorative Coin

[Helen U]

Hi - can anyone tell me anything about this?  It is very vividly enameled with all kinds of insignia on one side saying " Victoria Queen and Empress 1837-1887 The Longest and Most Illustrious Reign on Record" with a number at the base - 284223 and the other side Victoria Regina. 

It is almost 3D to look into and is 1.25 inches across and 0.1 inches thick and weighs 16.9 gms. 

I know it is a Jubilee but wasn't sure if it was a particular coin or particular medal or what kind of enamelling or other process makes it so vivid and clear.  Any info would be gratefully received.
Many thanks
Helen

[shanxi]

Without enamel you can find it here:

http://www.southafricanmedals.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=902&category_id=1&option=com_virtuemart&Itemid=1

[Helen U]

Thank you that's really helpful.  I wonder if it is rare with enamel?