Hey Cabin Fever,
I wrote one of those articles on my website about those gold plated copper nuggets. They are a lot less common than they were a few years ago, but I'm sure there are still some making the rounds out there. On one as big as 6 grams like yours, I think you would notice the odd size/weight difference... they kind of look realistic, but the weight difference is really noticable if you have handled a lot of gold.