What does the following reaction mean ?

i took a sample which was said to contain copper in it... when i mixed nitric acid to it... reddish- brown fumes came out in large quantities and the liquid became into dark brown color, i added a little bit of water in order to prevent the liquid from flowing out... i used a 100 ml beaker with 10 ml of nitric acid and approximately 1 gram of sample... what could the reaction mean ?? does it have high copper quantity in it ?? thank you for ur help :)