So there is a virtually infinite variety of quartz crystals around, of which Herkimer Diamonds are a type; differentiated by their uniquely beautiful habit* (shape and appearance) and occurrence (situation in which they're formed and found). Herkimer Diamond crystals are sometimes found in dirt only due to weathering over time, they've all come from two types of layers in the dolomite: what at the mine are called "Pockets" and "The Ledge".

"Pockets" are more or less what they sound like, relatively large vugs found in almost regular spacing along certain layers, they can range in size from about that of a basketball to upwards of the size a truck tire might occupy or larger. There can be virtually any type of Herkimer crystals within these pockets: big, broken, rust-covered cloudy ones packed in mud, or small perfect crystals and clusters in anthraxolite powder (though this is rare) and anything in between. Any clusters may already be popped apart or still be "naturals". There are also what are called "skeletal" crystals found in the pockets, these are usually larger than a small peach, and seem to be folded into themselves, leaving radial growth lines often trapping anhydros.

"The Ledge" layer is so called because it is below the pocket layer, miners cleaned off the pocket layer leaving a ledge. I'm told for a long time diggers disregarded or didn't realize this lower layer was crystal bearing, but now most will agree the ledge is where the finest crystals come from. The vugs within the ledge are usually lined with anthraxolite and are random in spacing and size, but seem to run in layers and it is unusual for them to be bigger than apples; it follows that the single crystals and clusters found in this layer are not as large as many pocket crystals, and in general skeletal crystals are not found in the ledge.

I expect most gentile readers of this guide will already be familiar with the most common, 18 or more sided, single crystal habit of the Herkimer Diamond; but I want to add more about the clusters and anhydros.

Herkimer Diamond crystal clusters are notoriously delicate in their natural form; and it is the rule rather than the exception that when you find a cluster it's already popped apart at the contacts between crystals. The best thing to be done in such a case is reconstruct the cluster which is what most diggers do, "natural" (un-popped apart) clusters are rare and treasured. If a digger finds a large pocket of small, popped apart clusters, it is literally a puzzle that can have 10s of thousands of pieces, all the same color and an added dimension, the 3rd., most miners consider the sorting and reconstructing of found crystals to be as fundamental in the process as breaking rock and finding crystal to begin with; so they're not "done" until they've been reconstructed.

Crystals with anhydros can be stunning and are a lot of fun. If you're looking at or for crystals with these you want to be sure to get one that is easy to see if that's important to you, some can be difficult but on the other hand some folks just want to know it's there. Also be sure that it's not somewhere in the crystal where it could escape, like next to or attached to a fracture that reaches the surface, especially if it's a freshly dug crystal. I'm told that some anhydro Herkimers shatter upon being in the Sun's light for the first time, since I've learned this any crystals I've found have been very quickly shaded, just in case, once they've been out of the Earth for a while they're ok. So if you have an anhydro crystal, be sure to take care of it properly: never leave it in a sunny or hot place like a window sill or a car in the sun since some may dry up (not all will). Worst of all for your anhydro crystal is letting it freeze, say by leaving it in your car or garden, this can break most any anhydro bearing crystal.

Herkimer anhydro with a mote of anthraxolite that moves when turned.