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What Rocks and Minerals are Worth – A Helpful Guide

Beautiful crystal specimens

All collectors would like to think that their collections are valuable. With most types of collections, it is relatively easy to know what a specific item is worth, but in the case of rock and mineral collections it can be very difficult to know what any one piece is worth. So how do you know how much a rock or mineral specimen is worth?

The value of rocks and minerals is determined by how well documented and cataloged they are, the quality of the specimen, perceived rarity, and sale history. There is no set value for any specimen. Ultimately their value is determined by what someone else is willing to pay.

Every rock and mineral specimen will have slightly different factors that play into their valuation. The same item or collection may go for very different prices throughout its life depending on how the quality, rarity, and sale history evolve over time. Understanding some of the nuances of specimen valuation can go along way towards finding out what your rocks and minerals are worth.

Properly Identify The Specimen

Of all the factors that go into valuing a rock and mineral, this is by far the most important. You can’t possibly know what anything is worth unless you first know what it is. Unfortunately, this crucial step is difficult for a lot of people. Maybe you inherited a collection from someone else or you’ve just forgotten where and when you found a particular specimen. Here are some things you need to figure out and some recommendations on how to go about it.

Know What it’s Called

If you have a rock or mineral specimen, you need to know exactly what it is. Hopefully it came with a label that you can trust or you have enough experience in identification to make the determination yourself. If you don’t know what something is and don’t know where to start I would recommend asking for help from one of two places:

  • Online Communities – Take several very clear, well-lit photos with something else in the field of view for scale. Post the photos with anything you know about the specimen on any one of a number of online communities asking for help with identification. You’ll probably find plenty of people willing to help. I would personally recommend starting at Reddit’s “What Is This Rock” forum.
  • Local Rock Shop – If possible, take your specimens to a local rock shop and see if they can help. Most of the owners and employees are pretty experienced in rock and mineral identification and will be happy to help if they have the time. Just make sure you don’t abuse their time. Plus, it can be helpful to establish a relationship with a local dealer if you even want to sell your pieces.

Find Out Where it’s From

Knowing where your rock or mineral originally came from can go a long way towards adding value. Depending on the type of specimen, there are some localities that are highly desirable to collectors. This is why it is so important to have a well cataloged collection that documents everything known about each piece.

If you don’t have a label for a piece you’re interested in, try to find out anything you can about it. If the specimen is yours, try to remember how you acquired it. If you bought it from someone, maybe you can contact them again and see if they have any records on the piece. If you found the specimen yourself try to think of all the places you’ve been hunting and try to match yours to pictures of other specimens found in those localities.

Chances are if the piece is worth any substantial amount of money then it will come with a label. If a specimen has been shoved into a box with an assortment of other unidentified rocks and minerals then whoever put it there obviously didn’t value it very much, so it is unlikely that anyone else will, either.

Make Sure it’s Properly Labeled

Speaking of labels, a quality and complete label will add a lot of value to a specimen. It doesn’t have to be attached to the specimen itself, but each item should have a system by which it is labeled and cataloged to keep track of all its relevant information.

My personal favorite method of cataloging specimens is to dot them somewhere not easily visible with white-out, and numbering it with black sharpie. Each number corresponds with a number in a separate catalog, where all of the information is recorded. If you inherited a collection look for labels like this and hopefully the accompanying catalog.

If the labels on your collection are torn up and inconsistent, consider re-doing them and making them look a little more uniform. If you are considering selling the collection in whole or in part this will add a bit of value to the buyer. If you learn anything about the specimens in your research be sure to add that to the label. Things like identification, locality, who found it, and when it was found are all relevant.

Know Each Specimen’s History

Knowing where the specimen was found is just one important part of its history. Depending on the location it was found, the year it was discovered can also add (or subtract) quite a bit of value for any specimen.

You may also find that who has owned the specimen may make them more valuable. If your piece has, at some point, been owned by a renowned collector or a celebrity then it will be worth more just because of the association.

If the specimen was purchased then hopefully the label includes the price it was purchased for. This isn’t always a good indication of what it is currently worth, but it is certainly a good starting point. Ideally you’d like to be able to value the specimen for more than it was purchased for but that simply isn’t always the case.

Examine the Quality

Once you know everything you can find out about your specimen it’s time to really examine the quality. There are a lot of factors that affect the quality of a rock or mineral specimen, and which factors are most important will vary from item to item. Knowing exactly what to look for times time and experience but these guidelines will give you a good idea of what makes a quality specimen.

How Aesthetic is the Specimen?

This is almost entirely subjective, but it also probably the easiest to determine for yourself. How ‘pretty’ is it? Do you just want to stare at it all day and show it off to your friends and family? If so, then it will be valued more highly than other specimens on the same type.

Maybe a rock has some beautiful foliations or interesting inclusion. A mineral specimen might have large, well-defined crystals in cool orientations. There are a lot of ways to define how aesthetic a rock or mineral is, and ultimately, beauty is in the eye of the beholder. What one collector thinks is a great piece might not be as highly valued by another.

How Clean is the Specimen?

This is something that is often overlooked by amateur collectors who find their own specimens. The amount of dirt and dust on a sample can have a huge impact on how much it’s worth. After all, would you want to buy something that is covered in dirt? Amateur collectors often just don’t have the patience or ability to completely remove all of the dirt and staining that comes on almost any find.

Luckily, you can sometimes add a lot of value to your specimens by doing some cleaning yourself. There are plenty of great resources online that will teach you how to properly clean various types of mineral samples. Really, all you’re trying to do is remove all the dirt and any iron staining from the item. This will leave only the rock or mineral that a collector is interested in and make sure it is ready for display.

Color and Luster

This is another part of the overall aesthetics of a specimen, but they are a little more quantitative. The color of rocks or minerals can very quite a bit, even among specimens of the same type. Similarly, the luster (how well it shines) can vary a lot and have a big impact on highly valued a specimen is.

Some colors of mineral types are much more highly valued than others. Which colors may vary with the collector – what one likes, another may not care for. If a new source of a particular color of a mineral is suddenly discovered then the market may become flooded and its worth will decrease.

Almost all collectors will value specimens with more luster than duller ones. They are just more pleasing to the eye and are more fun to display. For some rocks this may not be the case, but with minerals you will almost always find that shinier, more lustrous samples sell for more.

How Large Are Your Items?

While size isn’t the most important thing to consider when valuing a rock or mineral specimen, it is definitely a factor. In general, a high-quality, smaller specimen will be more valued than a lower quality, larger one.

Of course, all else being equal, bigger is almost always better. There are some thumbnail-sized specimens that go for a lot of money, but larger pieces of the same variety will be worth more. Dealers typically don’t care much about how large a specimen is as long as it is otherwise high quality, but some collectors are only interested in items of a similar size. They only want pieces that will complement their existing collection.

Is the Specimen Damaged?

Specimens that are whole and intact will clearly be worth more than broken or damaged ones. Damage doesn’t just mean that it’s broken – there could be internal fractures in the crystals or the surface may be worn from exposure to the elements or excessive handling.

Really take a good look at each specimen and look for any indication of damage. Large, flawless crystals will be very attractive to a buyer. Some crystals have natural fractures that have healed over. Sometimes this adds to the aesthetic quality of the specimen, but more commonly they detract from it.

Fractures aren’t the only thing to look for. Pockmarked or worn, dull surfaces will also detract from a specimen’s value. You would like to see smooth, shiny, flawless surfaces and crystal faces.

Are the Specimens Well Mounted?

Another consideration is if the specimen is mounted. And if so, how well? A well-mounted rock or mineral specimen is very attractive to a lot of buyers who would rather not have to go through the hassle of mounting it themselves.

A good mount is also a good sign that the item has been well taken care of and gives an impression of higher value. When you’re buying something you’d rather see it in good light, at the right angles, and feel like it’s well taken care of, right? Rocks and minerals are no different. If yours have quality mounts and look display-worthy they will probably be worth more to a buyer.

This isn’t always the case, though. For a lot of dealers and shops it may actually be to your detriment. They will likely want to remove the mount so that they can add their own to match the rest of their collection or displays. Sometimes removing the old mount can damage the specimen, so it’s an added level of risk for them.

Determine the Specimen’s Rarity

Rarity is a big part of what makes any specimen valuable. As with everything else, supply and demand is king. With rocks and minerals it is never easy to know what the market is like. It’s something that takes a lot of experience and knowledge in the industry. For more common rocks and minerals this isn’t a huge consideration, but for rarer and more specialty specimens it can have a big impact on their value.

The biggest swings in valuation tend to happen when a particular locality is depleted or closed. Once the source of those specimens is cut off, you will likely see their market value spike due to their perceived rarity. Similarly, if a new source of a rare specimen is discovered or an old mine is re-opened, you can see the market price plummet virtually overnight.

Locality isn’t the only thing that goes into the perceived rarity of a specimen, however. If you have a piece displaying a rare combination of minerals or it is an especially fine specimen then you’re in the money.

Know the Price History

If possible, it is great to know the price history of any piece you’re trying to evaluate. If you just found a rock in the field then obviously it has no history and you’ll have to start your valuation from scratch. But if the rock or mineral was purchased from someone else then it may come with records that include a price history. This is, unfortunately, pretty rare to encounter if you’re buying from a shop or dealer because they don’t want you to know how much they have profited from the transaction.

As a general rule you can assume that the more hands the specimen has passed through, the higher the price will be to you. All of the middle-men will want to make their cut and that cost will be passed on to you. If you’re wanting to sell a piece then you will want to get as much money as you can for it. All it takes is one buyer to value the specimen highly enough and you’ll be able to make some money.

Look at the Collection as a Whole

It’s not always necessary to know what a single specimen is worth. It is fairly common for entire collections or large portions of a collection to be sold together. Maybe you just found an old collection in the attic or inherited one from a relative. Maybe you have lost interest in the hobby or you no longer have room for it. In any case, it often makes sense to sell a lot of specimens together.

In this case I would recommend contacted some dealers and talking with them. Depending on the overall quality of the collection you could find one that is interested in purchasing all or some of the collection. This can be a lot easier than trying to sell individual pieces yourself and well worth giving them a bulk discount.

Some collections are specialized in one particular kind of rock or mineral. These can often be worth a lot more when sold as a unit than they would be by selling them piecemeal. See if you can identify any common threads in the collection. Maybe your collection is different varieties of tourmaline or all from a specific locality. If this is the case you will probably be able to hunt down someone else who has a collection specializing in the same thing, and they will be willing to pay a pretty penny for a lot of quality additions to their collection.