The Earth Story

Manly Beacon Trail Death Valley National Park

I bought a 365 nm UV light to unlock forbidden colors in my minerals. Top is my manganoan calcite I got last week at a rock show (most fluorescent specimen I have in my collection, it turns a pink-orange which is pretty cool) and on the bottom is my cassiterite (not fluorescent) but I found that uv light will shine on dust so it was kinda interesting.

The photo I have does not do the fluorescent property ANY justice, it is very bright IRL. Maybe I'll see if I can take a better photo in the future.

photo by Alexis Desjardins  (docileeffects.tumblr.com)

New Locations

One of the most useful things I’ve learned as a rock hound is how to locate new mineral sources. There are plenty of books and internet sources that can show you the major dig sites. This is good for beginners, but these sites can be crowded, mostly depleted, and often times left in a mess of tailings that you have to dig through to reach new material.

To start this off, definitely use local resources. Local rockhounding clubs and mineral societies often have plenty of useful info to get you started and occasionally have their own sites. Although I stick to my self and do my best to find my own locations, I will still occasionally use local groups’ sites and buy maps or guides to support them.

Maps are key. There are a variety of maps that’ll be a major help for finding mineral sources. I have four go to maps that I use regularly. I will go through three of the maps and explain how I use them, and then how I add it all up. Google maps (or Earth) is going to be a big help in getting an idea of the terrain and location.

First is geological maps. Obviously each state is going to vary, but this is the USGS map showing Washington’s surface geology. Other good sources of geological maps are geology schools or schools that have geology departments. I would regularly check Montana Tech’s maps while in western Montana.

There are two ways I utilize these maps. 1: learn a little bit of geology to figure out what host rock different minerals form in. This is a little bit trickier than the second method but if your a curious person and like learning new things it’s not too bad.

2 (match the color): pull up a geological map and a regular map like google. Find some well know prospecting locations and try to locate them on the geological map. After locating, you can observe what the host in that site is and look for other areas with the same host rock. For example: A well know site near me for geodes and agate has a surface geology consisting of tertiary volcanic rock (Tv, brown). I can take that and simply look around for other brown areas on the map. I’ve used this method a few times and can even match it with other known dig sites. I also like to use google maps to see if there is exposed rock or Boulder fields in the area for easy access.

The Diggings have a very useful website that I utilize regularly. The black diamonds show documented mines, prospects, and placers. The blue boxes are current and expired mineral claims. I like to use this map to find where clusters of mineral claims are to find what can be in the general area. It’s also useful to make sure you aren’t on someone’s active claim. It’s always safe to check with the Bureau of Land Management, just to be sure.

Finally is OnX maps. I currently do not have their product downloaded so I can’t show a photo. This one isn’t involved with rockhounding but the hunting version is incredibly useful. OnX maps shows accurate land boundaries along with ownership. It does not show mineral claims but it is helpful in knowing where you are and making sure you are on lands where you can legally prospect. It also has multiple layers that you can customize, route tracking, and saving maps to use when offline. I believe the hunting version is $30 for a year of one state or $100 for the entire US, but don’t quote me on that. Also, I do not have a partnership with this brand. I am simply a very satisfied customer.

So that about sums up how I locate new deposits. There are plenty of other methods and resources you can use out there. Hoping this provides some help to anyone interested. I apologize for the long post.

A little fish 🐠

Quartz outcropping. John Muir Wilderness, Sierra Nevada Mountains, California, USA. Photo by Van Miller

Another set of pics from the Dinosaur Research Center.