Welcome

This website presents the photographic record of a collection of over 5000 lots of agates and jaspers acquired over three decades by an avid rockhound.  (In 2021, the collection was donated to three museums, in order to share it more broadly.  This happened in three steps, and photographs of donations to the first two recipients were removed from the website.  The present state of the website contains only the largest donation of ~3000 lots.)  This hobby was motivated at first by the great natural beauty that can be found inside certain types of rocks from locations all around the globe.  And second, by the great detail that is often found in microcrystalline quartz – detail that provide hints and ultimately clear evidence for the mechanisms by which these structures developed over geological timeframes in environments that lay hidden below ground.  The latter focus led to three papers based on this collection:

1. Dehmer, Agate Genesis – Three Persistent Questions, Rock & Gem, March (2019),
2. Dehmer, “Orb” Structure in Porcelain Jaspers – Origin of an Enigmatic Phenomenon, ibid, June (2019) and July (2019),
3. Dehmer, Dinosaur Bone Agates – A Full Display of Agate Phenomena in Miniature, ibid, November (2019).

There is an substantial literature of studies of agate/jasper phenomena, which started back in the classical period of Greek culture.  The present purpose is simply to document a diverse collection by means of a comprehensive photo gallery.

Organization

The collection has been organized into 26 major categories (two for plume agates), which can be accessed by clicking on elements of the menu at the top of each page.  The menu contains seven primary categories (agates, jaspers, petrified wood, fossils, jade, obsidian, and other).  Three of these have inverted triangles next to them, indicating they expand into dropdown menus listing subspecies of the primary menu item.  For example, if you hover the cursor over Agates, a dropdown menu appears that contains 10 types of agate.  Hovering the cursor over one of these submenu items launches the web page containing all the photos of that group.

For example, selecting Fortification Agates, from the Agate dropdown menu will produce a page with groups of photos for each of the types of fortification agates in the collection.  At the top of the Fortification Agates page, a table will give the names of fortification agates included, in this case 24, from Agate Creek to Wave Hill.  The elements of this table are not links, so the individual types of fortification agates are accessed by scrolling down the page, where each will be set off by a bold heading.

So you have selected a main category, then a sub category from the dropdown (if applicable), and you have scrolled down the page to the set of pictures corresponding to the species you are looking for.  In each case there will be an array of thumbnail photos immediately after the bold heading.  If you hover the cursor over a thumbnail photo, a brief caption will appear, giving basic information about the item pictured.  If you click on the photo an enlarged picture will fill the screen, with arrows to the left and right sides of the screen, allowing navigation to other photos in the set.

Copyright 2021