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display of copper minerals

Before you start collecting a lot of minerals think about how you are going to store and display them.

from 2011

Mineral Articles

Mineral Storage Factors

page 1 - thinking about storage

I was showing some minerals to a friend and one of the specimens triggered his memory of a fantastic find he had a made a few years back. I had been to his house and I had not seen the specimen; he explained “its packed in a box, somewhere in my mineral storage”. My friend has a lot of rocks. I have have a lot of rocks too - how should we store them?

1st think about why you collect minerals?

Rock and mineral collectors bring home a lot of rock usually for a good reason. Large quantities of rocks are required to supply the kids games and specimen tables at Rock and Mineral Shows.  Minerals need to be cleaned and trimmed. A collector might clean and trim several specimen before getting one to display well. Also, having a few good specimen to trade with other collectors is essential to making the time spent digging economical; and at least one extra nice specimen is required for the annual club Christmas exchange. Whether you buy your minerals or field collect you are likely to end up with a lot of minerals in boxes.

What you eventually do with your minerals is tied to your reason for collecting minerals in the first place. Some individuals love the discovery, finding minerals is more important to them than displaying their specimens. Some collectors are primarily interested in the mineralogy of specimens, scientific study rather than display. I collect mineral because of their beauty and have a driving curiosity about their formation, particularly in their crystal form. Every mineral I acquire is an opportunity for me to learn more about the geological world.  I also like to share my discovery with others, so I focus on minerals that will work well in displays.

My mistakes guide me in the storage and display of my minerals

Mistakes I made  (and some things I did not know) when i started collecting minerals:

          1. I brought home minerals with out a safe place to display or store them. A few of my minerals have been damaged by improper storage.

          2. I did not consider that some rocks and minerals can fade under sunlight.

          3. While I had read some minerals can dehydrate over time. I did not know and still do not know exactly how this will effect some minerals.

          4. I was not aware, and I am still some what concern about, how some minerals might interact with each other.

          5. I did not know what pyrite disease was and that it could infect other pyrites.

          6. A few times, arriving home with a new mineral find, I unpacked it, and then remembered a few hours latter the locality label were mixed in with the packing material; luckily, the trash had not been picked up.

          7. I did not consider freezing (or heating) could fracture crystals with liquid inclusions. I recently was told that even handling a sulfur crystal can cause it to fracture due to unequal heating from the touching.

What to do:

          (1) Some minerals are resistant to damage and can be displayed in public areas with out, to much fear of damage; i.e. vain copper, a quartz bolder. Rocks, and minerals, which do not hold a lot of value but are still decorative and interesting (like pegmatite) can be displayed with out protection; some even can end up as lawn ornaments.


If you just spent a good sum of money (or a days work of digging) on a nice mineral specimen, have a secure and proper place to store/display it. Open shelving (where I have many of my specimens) is not proper storage for display minerals. Open shelves may  mean regular cleaning of your specimens to remove dust, and for many minerals dust is an abrasive (mohs hardness equivalence of 5). For your best quality pieces you will want to avoid any extra handling, which also means limiting the cleaning required. You can store items in boxes or drawers but if you want to view your collection or show it often to others then an under glass display is likely the best option. 

          (2) Some minerals known to fade with long term exposure to light are Vanadinite, Amethyst, Fluorite and Kyanite. A few minerals are very light sensitive; Vivianite and Realgar for example (Realgar will turn to an orange dust after a several months of bright light exposure; green Vivianite will quickly darken and change to a dark blue/black with a few days exposure to bright light). Display cabinets should be kept away from direct sunlight. When not showing my minerals to others I keep their cabinets covered to limit their exposure to light. Vivianite and Realgar should be stored in the dark to preserve their color.

          (3) Mineral dehydration due to heat or direct sunlight can occur in some mineral groups; for example the  Zeolites and Apophyllite’s.  As I understand it, the crystal form of the mineral may be retained but the mineral may not look as attractive. Example: translucent Borax crystals when dehydrated will become opaque, altering in to the mineral Tincalconite, eventually then turn to dust. Solution, do not let heat build up with in your display cabinet or put specimens in the sun. If you want internal lights in your display cabinets, any heat created by them will need good venting. LED lights produce little heat. Depending on the mineral, a slightly humid environment can be a good or bad thing, it is not always easy to determine the ideal environment for your mineral collection. 

          (4) When admiring their beauty It is easy to forget that minerals are chemical compounds. The minerals that end up in mineral collections are usually stable but a few could pose a danger to other specimens. I have read that under some conditions sulfides can breakdown (interact with the atmosphere) and produce a sulfuric acid gas. In the confiding space of a mineral cabinet, sulfuric acid gas will likely have time to react with some minerals in your collection.

          (5) Pyrite disease is initiated by the break down of pyrite due to humidity -  you can read all about it here.

       (6) Don't forget the label. In the excitement of buying a mineral specimen, or unpacking the specimen, it is easy to leave the label behind.  If you are looking to display your minerals, use them for scientific study or resale them at some point, having locality information is essential. In the process of packing a mineral it is easy for vendors to forget to include the mineral's label too, you need to watch closely.

     (7) While many rocks and minerals can survive freezing and high temperatures you will want to avoid both for the specimens you value.  Crystals with water and air bubbles have been know to crack and even explode when heated by a display case lamp. Many crystals have also been damaged when internal water bubbles have froze, fracturing the crystal. It is good form to ask before handling another persons specimen, just the  heat from your hand can damage a sulfur crystal.

Next: Page 2, some thoughts on home Mineral Display Cabinets


How do you want to store your rocks and minerals? There are several options, box storage, display storage, pile storage, outside storage, the list goes on...

Red realgar crystals on calcite. When exposed to light for a period of time these crystals will covert to a new mineral, an orange dust.

Fluorite  crystals

This Fluorite look like it was a solid purple when bought but after 20 years in a north facing window the yellow fluorite is showing through the faded purple fluorite.

Stilbite on Apophyllite - Stilbite is a zeolites. Zeolites should not be stored in extremely dry environments. It does not hurt to hit them with a spray of distilled water during the year.

Native Sulfur - will tarnish silver specimens kept in the same box or cabinet. It may also react with the atmosphere to produce a mild sulfuric acid.

Marcasite - has the same chemical formal as pyrite but a diffrent crystal structure. The crystalline structure of Marcasite is not as strong as pyrite's.  It is more likely to get pyrite disease.