I took it to the gold buying shop to ask for analysis on their machine. I was told it was not gold...even though it looks like it in color. It is a very golden yellow. The jeweler said the color was surprising as it did not analyze as gold. He referred to his chart and said it included palladium, rhodium, silver, and pyrite. To me the reverse of the crystal side looks like the outside of a geode but it has some small crystals and trace color too. I saw a specimen on line that looked like it and it was iridium along with those metals I mentioned above. Any ideas. Thank you. I purchased it as a pendant from an online auction. No details as to where found, etc.