Practical Rock & Mineral Identification
By Currently Rockhounding
The topic of identifying rocks and minerals will inevitably come up when you enter the hobby and it comes up on a daily basis if you’re part of any online community. This is the simple method that I use for rock and mineral identification. I know it isn’t the most scientific way to identify a rock, but it gets the job done in most instances and it’s what I have been doing with great success for sometime now.
There is no way to really complete all of rock identification steps without purchasing some items so I have included a few links to the tools on Amazon because I earn a small commission from qualifying purchases made after clicking one of my links, even if you ultimately choose another product. This costs you nothing, but the small commissions earned on referrals supports the ongoing creation of content on this site. Thank you for your support.
The big ticket item for this is the Mohs’ Hardness Test Kit from Mineralab which you really can’t go without and is far better than the DIY kit people suggest and that will be addressed later.
You will also want a couple books which are pretty common and can be found on Amazon and they are in most library systems. A Field Guide to Rocks and Minerals Peterson Field Guide and Smithsonian Handbooks: Rocks & Minerals are books that make for excellent reference tools.
When attempting to identify a rock or mineral you will want to ask yourself the following questions:
Where did this rock come from?
Is this rock magnetic?
Is this rock metallic?
What is the hardness of this rock?
What is the specific gravity of this rock?
What is the luster of this rock?
What is the color of the this rock?
What is the grain of this rock?
I show you how to answer these questions in detail in the video below.
Two topics not covered in the video were ultraviolet light reactions and radioactivity. Both of these are huge subjects in their own right and will be covered in future articles.
The price ranges for UV lights run from your really cheap 395NM light for $6 all the way up to a really big professional UV light for $1500+ and similarly a Geiger Counter can cost between $75 and $3000. Ultimately you get what you pay for with these.
The UV light I currently have (April 2021) is the uvBeast V3 Filter 365NM and my Geiger Counter is the GQ GMC300EPlus, both of which are on the cheaper side but function well in the ways in which I use them.
Lets talk about this DIY hardness test kit that people have been suggesting based on this image here.
I have no idea what the origin of this image is but it is not accurate when compared to a legit hardness testing kit. When compared to items of known hardness things like nails, screws, knives, and drill bits all have large variation in hardness and the the difference between a 5, 6, or 7 is pretty big and really can rule rocks in or out when using hardness picks to identify rocks so it’s important that your hardness testing be accurate.
I hope you found this article to be informative.
Left to right the rocks in the above photo were Agate, Red Marble, Quartz with Copper Ore, and natural Asbestos.