Denver Gem & Mineral Guild

Useful Links

Below is our curated list of links for useful resources of interest to the mineral community.

Free Ebooks

From the Colorado Geologic Survey

Golden Rocks: The Geology and Mining History of Golden, Colorado by Donna Anderson and Paul Haseman. This brand new beautifully illustrated 100+ page ebook tells the fascinating and often surprising facts about Golden CO and its geologic history. It is now available for FREE from the Colorado Geological Survey.

Hundreds of other free downloadable books, maps, reports, plus GIS data can be found from the CGS here.

Issuu,.com offers a wide variety of books, magazines, phamplets, and short reports on just about any topic you can imagine –  including gems and minerals – all for free.  A few can be downloaded for offline reading, the rest can be read directly on the site. Simply use their handy search bar and prepare to be amazed at what comes up!

The Internet Archive:

The Internet Text Archive contains over 36 million books, periodicals, and other documents on every topic imaginable, which are available to either borrow or download. Since 2005, the Internet Archive has collaborated and built these digital collections with over 1,100 Library Institutions and other content providers.

Extensive search options are available to help you find your desired materials. For a tour and assistance in how to search the archive, check out this helpful video – How to use the Internet Archive.

Free Colorado Field Trip Guides & Virtual Field Trips

Colorado Points of Geologic Interest – interactive map by Colorado Geologic Survey

The Geology Along the Trails West of NCAR – Emmett Evanoff and Sue Hirschfeld, Colorado Scientific Society

Geology of Marshall Mesa Open Space Boulder, Colorado – Sue Ellen Hirschfeld and Peter Stevenson, Volunteer Naturalists, City of Boulder Open Space and Mountain Parks

Field Guide to the Old Kiln Trail, Boulder, Colorado – Sue E. Hirschfeld, Ph.D. City of Boulder Open Space and Mountain Parks

Denver Downtown Building Stones Virtual Field Trip – Rocky Mountain Association of Geologists (RMAG)

Golden Rocks! Geology and Mining History of Golden, CO – Virtual Field Trip – Donna Anderson (RMAG)

Debris Flows along the Interstate 70 Corridor, Floyd Hill to the Arapahoe Basin Ski Area, Central Colorado – a Field Trip Guidebook – Jeffrey A. Coe, Jonahan W. Godt, ad Alan Henceroth

Guide to the Geology of the Glenwood Springs 
Area, Garfield County, Colorado – Colorado Geologic Survey

Guide to Laramide Structures Along the Northeastern Flank of the Front Range– Vince Matthews, Colorado Geologic Survey

Geology of the Gold Belt Backcountry Byway, South Central Colorado – Colorado Geological Survey

Geologic Wonders of the Hart(sel) of South Park – Peter Barkmann, Colorado Geologic Survey

Northern Never Summer Range VolcanicField – The Search for Braddock’s Caldera – Ed Larson, CU Geology, Jim Cole, USGS, Kark Kellogg, USGS, Lang Farmer,CU Geology

Volcanic and Plutonic Rocks of Table Mountain – Harald Drewes

Guidebook to the Proterozic Accretionary Terrane of the Central Colorado Front Range – Lisa R. Fischer and Thomas R. Fischer, Colorado School of Mines

The Colorado Front Range, Anatomy of a Laramide Uplift – Karl Kellog, Bruce Bryant, and John C. Reed, Jr, USGS

Laramide and Precambrian Geology and Tectonics of the Central Front Range with Emphasis on the Laramide Tectonics and Precambrian Accretion of Colorado – Dr Robert J. Weimer, Prof .of Geology Emeritus, CSM, Lisa R. Lytle, Ph.D. Geology Candidate, CSM, Dr. Thomas L. Davis, Prof. of Geophysics, CSM, Thomas R. Fischer, Ph.D. Geology Candidate, CSM

Field Trip to Northern San Juan Volcanic Field – Peter Lipman

Colorado Front Range Self-Guided Geology Field Trips – Uwe Richard Kackstaetter, Ph.D.

Proterozoic Metamorphism and Deformation in the Northern Colorado Front Range – Kevin H Mahan & Julien M Allaz, University of Colorado, Graham B. Baird, University of Northern Colorado, Nigel M. Kelly

Geologic Excursions to the Rocky Mountain and Beyond – 28 field trip guides to parts of Colorado and surrounding states – Colorado Geologic Survey

A Dash with Dinosaurs: A Mountain Bike Trek to the Purgatoire River Dinosaur Trackway and the K-T Boundary Impact Layer of SE Colorado – Colorado Geologic Survey

Guide to the Petroleum Geology and Laramide Orogeny, Denver Basin and Front Range, Colorado – Colorado Geologic Survey

The Slumgullion Landslide, Hinsdale County, Colorado – Colorado Geologic Survey

First North American Landslide Conference (NACL) in Vail Colorado, 2007 – Colorado Geological Survey


GemCad & GemRay

As of January 2023, GemCad & GemRay are now FREE!

GemCad is a computer-aided design (CAD) program for faceted gemstones. It runs on PC compatibles with Microsoft Windows 95™ or later. Its final product is an accurate faceting diagram that you can take to your faceting machine and cut.

GemRay renders images of gemstones using the technique of ray tracing. The purpose of GemRay is to predict what a faceted gemstone will look like when it is cut and to optimize its angles for the best optical performance. GemRay runs on PC compatibles with Windows XP™ or later.

With GemCad, you can be assured that a faceting diagram will produce the gemstone pictured without unnecessary fiddling with angles. With GemRay, you can be assured that the geometry in the diagram produces a stone that sparkles the way that you want it to.

The Learn page has links to videos on YouTube that introduce both programs and teach you how to use them.


See the extensive list of software available on the Mineral Collectors Page.

Mineral Information, is the world’s leading authority on minerals, their identification, localities, deposits, and mines worldwide. An international team of 50 expert managers work to ensure its accuracy.

It’s an extensive site with many incredible features. You may find this user manual helpful in learning to navigate it. Also be sure to view this informative interview with Mindat founder Jolyon Ralph where he does a walk-through of the site.

(The Denver Gem and Mineral Guild is a sponsor of Mindat!)

Amazing Geologist

Amazing Geologist is a Facebook page that features georgeous pictures of minerals, fossils, structures, gems, geology, etc., with simple information on the content. Started in 2012, collectors worldwide contribute their photos.

Their fabulous photos are widely shared throughout the Facebook community.

Geology In

Geology In is a blog site with a very large collection of blog posts (including beautiful pictures) about minerals and other geology topics. The site is constantly updated and the articles are searchable.

They also have a nationwide listing of upcoming mineral shows.

Chercheurs de Verites (Seekers of Truth)

Chercheurs de Verites – More geologic eye candy from around the world – many pages to explore.

This site is in French, but you can find the option to translate to English in the upper right-hand corner of the site.

Rock&Gem Magazine

Rock&Gem magazine started in 1971. It has been the leading magazine for the lapidary and mineral hobbyist.

Their website offers an extensive collection of blog articles, a free Digital Issues Library, videos, and lists of clubs and shows

Also be sure to check them out on Facebook and Pinterest, or try their new phone app

And be sure to read their April 2023 article featuring our own Ron Snelling on How to Start Gem Cutting.

Rock Seeker

Rock Seeker is a blog with beautifully illustrated, easy-reading, non-technical articles of interest to the rockhound community. You can subscribe to their free newsletter to be notified of new posts. You may also want to check out their Facebook group.


There are countless pages on Pinterest dedicated to rocks, minerals and fossils. Here are just a few to get you started:







Gem Rock Auctions

Gem Rock Auctions is an auction site with some useful learning resources. Check out their Gemstone Encyclopedia, Opal Encyclopedia, Jewelry Encyclopedia, and Coin Encyclopedia.

International Gem Society

IGS – founded in 1998 by the late Donald Clark, IGS is the world’s top resource for gem professionals, enthusiasts, and industry content. Their website features numerous articles, a searchable Gemstone Encyclopedia with in-depth information on over 300 types of gemstones, a Gem Price Guide, Expert Buying Guides, Business Listings, A Guide to Gem Cutting Styles, Q&A Forums, and more. 

Join their weekly newsletter and get a free copy of Gemstone ID Checklist: 17 Practical Steps to Identifying a Stone.

Mineral Collectors Page

The Mineralogical Society of Antwerp, Belgium was founded in 1963 by a small group of mineralogy enthusiasts and has since grown to an active club with over 400 members. Their members are amateur mineral collectors, students as well as professional mineralogists, all with the same joint interest in minerals.

Their site contains an impressive collection of links of interest to rockhounds of all ages worldwide, including: Gems and Gemmology Education Resources, Diamond Dan Publications for young mineral collectors, Educational sites & on-line courses, List of worldwide mineral museums and online virtual museums, online mineral databases, software, free mineralogy book downloads, Gold Maps online for active and abandoned mining claims using Google Earth, Mineralienatlas – thousands of mineral localities, Treasure Net – for gold panners and treasure hunters, and much much more.

Online Mineral Galleries

MINES Museum of Earth Science

Visit the Mines Museum of Earth Science Photo Page on Flickr to view over a dozen pages of beautiful rocks, minerals, and fossils.  Guess the name of each, then hover your mouse over the image to reveal the name.

The Mines Museum regularly displays minerals from their fabulous collection at our September Denver Gem & Mineral Show.

Mineralogical and Geological Museum at Harvard 

 The Mineralogical and Geological Museum at Harvard University (MGMH), is home to one of the finest collections of geological material in the world. Over two hundred years of attentive curation has resulted in a premier collection of more than 400,000 specimens. The MGMH functions as a repository of geological material to further Earth Science research and education at the university and around the world.

The Harvard Museum frequently displays minerals from their collection at our September Denver Gem & Mineral Show.

The Smithsonian’s mineral and gem collection at the National Museum of Natural History consists of approximately 350,000 mineral specimens and 10,000 gems, making it one of the largest of its kind in the world. Along with the specimens highlighted here, the world-famous Hope Diamond and hundreds of other spectacular items from the collection can be seen in the Smithsonian GeoGallery. The Smithsonian is also a long-time exhibitor at our September Denver Gem & Mineral Showbut we’re still waiting for them to bring out that diamond. 😉

See And Do in Colorado

A global community of explorers, who have created a comprehensive database of the world’s most wondrous places and foods —26,954 of them contributed by our community so far, and more every day.

Explore their database of amazing things to see across Colorado and around the world.

Out There Colorado

Out There Colorado,  part of the Denver Gazette, covers stories on Colorado Geology, History, Recreation, Events, and other News. You can browse the site by their various categories. Unfortunately, they have no “search bar” to search for a specific key word.  

But here is a trick you can use to search ANY site for ANY topic. Simply go to Google, type “site:” enter the url of the site, and enter your keyword, eg.

site:   mining

That example would list all the pages on the Out There Colorado website that have the word “mining”.

Mile High on the Cheap

Free and Cheap things to do in Denver this weekend

Video Resources

Blue Cap Productions

Check out the Blue Cap Productions YouTube channel for video coverage from mineral museums and shows around the world, along with interviews and lectures by numerous mineral collectors, mineralogists, miners, museum curators, and other notable figures in the world of minerals.

In this video you can hear how founder Bryan Swoboda came to create this channel and learn about their mission and plans for this endevor.

Highland Park Lapidary

Highland Park is a supplier of lapidary equipment.  Their YouTube channel has over four thousand subscribers and covers nearly every aspect of lapidary arts. They include entertaining shorts, and various videos focused on a specific topic like “gluing slabs together with UV glue”. Subscribe to their channel to be notified of their live webinars.

This page last updated 3/4/2024