Just a word of warning about moldavite: There is a LOT of fake moldavite out there. Before you buy, do your research and understand how to identify the fake material. And only buy from reputable sources. I know many people who have gotten scammed with moldavite (and other stones, too).
I would imagine references are the chief way to identify fake moldavite online. As for in person, being able to feel the energy would help. The energy of moldavite is POWERFUL. You'd feel it straightaway & it'd affect you for (in my case) hours afterwards. When I first held it energy shot up my arm & through all my chakras, like
Energy is how I identify whether a rock is what others say it is. I can feel it from pictures too