It’s cool that you found that! You can try identifying it by its luster, color, breakage, etc, Try getting a piece of paper or something, scrap it on the paper, and see what it leaves behind. That’s a way many scientists identify rocks/crystals. You can also google types of rocks and see if you find a match. You always need to look at its color, as the color is the most distinctive feature of a rock. If you’ve since all of these things and your very serious about it, you can try calling somewhere or someone who would know (like a scientist who studies rocks).