This item was originally called Golden Mace and at some point was renamed to Light Mace.
In the Spring Patch of 2012 (Update 9.5) the sprite changed from to
As far as I know there is currently no instance of this in game. There was an old rare collector on Antica named Mulf that claimed to have solved the quest to obtain it. This interview is from 2007.
"Are there many other ppl with those rares? Give some example of items you found. Do you think Cip Soft hidden them well?"
"On Antica are a few people with a great axe, winged helmet, blue tome etc. Mostly they rot in depots tough. Some rares are also items which you can normally get now after all the updates. The "Dark Shield" for example, only me and a friend owned it, later it got into a lowlevel chest-quest. Items i found would be for example the Silver Mace (Baumbart helped me with this one), Golden Mace, Brooche, Soft Boots (they look like those new boots of waterwalking) Later on, i also reached it to get a Warlord Sword via questing. Items i own and have owned which are still rare were the Silver Necklace, Bronze Necklace, Great Axe, Winged Helmet, Horned Helmet, Great Shield, Helmet of the Stars and of course typical rares too.
And yes, CipSoft really did great work concerning quests for such items. Now in tibia it seems like you just have to kill creatures to get rares, but concerning quests where you have to use your brain mostly, they really did a good job in creating them."
Also, I remember hearing rumors so I wouldn't believe this part. If you do believe them it was that the Golden (Light) Mace was found at the Spike Sword quest at Fire Devils behind the Magic Walls that is cannot be reached.
https://web.archive.org/web/20130105111351/http://www.tibiacity.org/p/39/mulf_antica_rare_collector (the original URL is no longer active, you must look at the archived version)