Stone Identification: Is Your Crystal Valuable? - Expert Advice

Question

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Img 2   Hello my name is kylie and I recently found a stone I'm wondering if it has any value. I googled some of it's traits online and thought maybe it could be a quartz because it has little bubbles in it . Also in the middle there is little prisms and I see a tiny rainbow spec in there to. It could just be any old crystal but I just would rather know than not know !
Thanks, kylie

Answer
Hi Kylie,
Identification from mineral pictures and descriptions is always a little difficult. However, there are some indicators that might be helpful. Quartz is a very good possibility since it is incredibly common. The described bubbles would also be common in certain quartz varieties. If you find that some of these bubbles are filled with liquid, then your specimen will hold some value for rock hounds and collectors, but nothing groundbreaking. The rainbow inside the rock is most likely produced by a tiny crack in the specimen, which would refract the light through a small layer of air now sandwiched between two crystal pieces. This would create a rainbow effect.
Sometimes it helps to know where you found the specimen since this might give additional indication of what it could be.
To be sure you could test the mineral on a piece of glass and see if your specimen scratches the glass. That could be an indication for a hard mineral, such as quartz.
To be absolutely sure you can do a density test on the specimen. Quartz should be around 2.65g/cm^3. If you get a significantly different number you should contact me again. I have published an article in "The Professional Geologist" on how to do this very accurately. Here is the link to download the publication: http://64.207.34.58/StaticContent/3/TPGs/2014_TPGAprMayJun.pdf The article is titled "A Rapid, Inexpensive and Portable Field and Laboratory Method to Accurately Determine the Specific Gravity of Rocks and Minerals" and can be found on pages 56 - 60 of the publication.
Hope this helps.