Well the first thing you did right was to FIND IT! Awesome nugget, I've never seen one quite like it!! What country was it found in? Then you've plenty of good light with a dark background and the nugget is on top of a contrasting color. A tripod is a good idea as it reduces any shaking or body movement when hand holding a camera though that means the camera must have a tripod mount built into it.
Depending on the camera model/brand/type, it is possible that it has a menu of types of photographic situations (landscapes, closeups, people especially from the shoulders to the head) and assuming the camera is digital, it would be useful to experiment with taking pictures to obtain focus on objects at close distances. But again, the lighting for your nugget picture is good and bright and that allows the automatic adjustment inside the camera to to use settings that increase the depth of focus for the picture. Taking closeups is tricky even more so in a macro setting so experiments are very worthwhile. Good lighting, use a tripod and use the timed release setting/remote control if the camera has one as then there is no camera shake when pushing the "shutter release button". And if you can not use a tripod then brace your arms against something to reduce shaking/blurring the camera/picture.....63bkpkr