95% of the cleaning work has been done before I purchase minerals for inventory. I’m not out in the field digging it up myself (yet! will do manual labor for cheap rocks, you know where to find my email). I buy wholesale lots at the Tucson Gem & Mineral show, from the people who do the digging.

Cleaning is the first step of preparing things for sale, and it gives me a chance to study the material closely and start to understand it. Cleaning has unveiled undisclosed repairs! I always give each mineral a once-over to dust away loose pieces, dirt, and debris. If it is safe to do so, I wash minerals.

Caution: I do not recommend cleaning your own minerals if you are not relatively knowledgable about minerals and confident the material will not be damaged. Do your research. There are minerals that can be damaged even by something as simple as light handling, a soft paint brush, or water. I heard a horror story about a person who put a piece of halite (mineral salt) in the bird bath as decor and thought someone stole it overnight when it dissolved!

 

What needs cleaning?

• Oils: am I imagining it or are more people over-oiling the minerals they are selling wholesale? Oil seeps through plastic bags and leaves spots on surfaces below. Minerals are oiled because it fills surface fractures, giving the piece better color and clarity. Oiling is normal practice, it just seems like people are overdoing it lately. I find oil can dull the surface and I hate it touching anything, me included. When I can feel that greasy, gritty surface, I give the minerals a bath with a small amount of Dawn dish soap. It often takes a few soaks with soap, a rinse in water, and rubbing it down with a clean cloth to remove most of the oil. It is a helluva lot easier to get oil into a tight fracture than it is to get oil out of a fracture, so oil will always remain in the mineral and can continue to seep out of fractures after multiple cleanings.

• Fingerprints: Again, oils. If you’ve ever had a job that involved keeping a surface clean of hand/fingerprints, you’re aware of how disgustingly greasy humans are. We leave oil marks on everything we touch. Fingerprints can be super obvious on shiny and dark minerals like smoky quartz. I use a gem cloth or glasses lens-cleaning cloth to wipe them away. Professionals use gloves to handle minerals to avoid fingerprints in the first place.

• Dirt: sometimes minerals have not been very thoroughly cleaned of loose materials covering the crystals, including dirt and matrix. BATH TIME! Straight water, no soap this time. I use wooden toothpicks and paintbrushes to remove clayey dirt without risk of scratching the mineral. Sometimes just sloshing it through the water a bit is all it needs!

• Dust and fuzz: this is especially common when minerals are wrapped in toilet paper or paper towels for cushioning in wholesale flats. Some types of toilet paper in particular can leave tons of fibers on minerals. I give pieces a gentle dust-off with a paint brush.

• Spider webs: I was perturbed to discover how often I’d come across webs. Minerals can sit in storage or collections for years before going up for sale though. I use a paintbrush to remove webs. Except the one on the specimen you ordered, that guy looked mad so I left him in there.

• Pet hair: okay that may be happening on my end. I promise I really try not to send hair out in your packages!

 

I try to provide scale images for all items sold. Many items are photographed on a cutting mat using the ruler grid for scale. I've realized this can actually create an illusion that some minerals are larger than they are in reality. If you are wondering why there is a discrepancy between the listed dimensions and the dimensions in the photo, this is the likely reason.

The other reason is because it can be a bit tricky to even decide which dimensions of a mineral to measure, so I tend to use averages when something is wompy shaped. I err on the side of rounding down on measurements; I’d rather you receive something a bit bigger than expected than something underwhelming.

All measurements are listed as "approximate" just because even with the cleanest specimens you will have slight variations if you measure them in different places. If you need specific measurements for any purpose such as jewelry-making, reach out! 

I usually do not include protrusions in the total dimensions either, simply measuring the main body of the specimen. Let's call this one two and a half inches:

I sometimes photograph minerals I am holding, since a hand provides a sense of scale that is easy for the layperson to understand. Beware it is a known scam in online sales to use a child or very small person holding a specimen to trick you into thinking it is much larger than it actually is! I am an above-average sized person but don't let your guard down; I do have small lady hands that may make specimens look more impressive.

 

Lighting

I am not a professional photographer and I hope that’s not obvious! I use bright direct or indirect natural sunlight for most of my photos. Lightbox photos (those with a white ‘wrap’ background) use daylight-equivalent lightbulbs.

You may notice a specimen appears different colors in different photos. I have tried to correct for that in edits to an extent, but sometimes it is deliberate. Minerals and gemstones actually can have a very different appearance in different lightings, so I try to include images illustrating this. 

The UV lights I use when photographing—and enjoying my collection—are from Way Too Cool. The UV flashlight I use the most is their Convoy C8+ 365nm UV LED Flashlight. It can actually be too powerful and bright so sometimes I switch to a lower-powered model.

If a mineral fluoresces I try to include an image of it, but fluorescence can be especially difficult to photograph. The camera can try to pick up the UV light itself, or reflections of it, and gets confused by bright reactions in the dark lighting. Something like fluorite ends up looking like a blown-out blue smudge. If there is no photo it’s because it wigged out the camera a bit!

Editing

I wish I could use all my pictures without edits but some minerals are hard to capture on camera! At least for my amateur ass using an iPhone 15 Pro. But this is true even for the professionals; dioptase is supposed to be one of the most difficult minerals to accurately capture the color of in photography.

Photos are minimally edited, with most simply needing cropping to improve focus. Some images have color adjustments, but only with the aim of matching color and appearance as closely as possible to reality. I am an amateur photographer and I may have an imperfect eye for color, but I hope my experience with the nuance of grading gemstone color has developed some accuracy here.

When I edit photos it’s most often adjusting brightness levels and normalizing warmth level. I'm never cranking up the color saturation to trick you into buying something... half the minerals available are some shade of brown and I'm trying to convince y'all to appreciate them just the way they are anyway.

 

There are a lot of things that impact the value of a specimen, beyond a matter of simple rarity. I share this in part for transparency on the process, but also to help you understand what factors to consider as you develop your eye as a collector. Understanding how value is determined may help you spot when something is overpriced. Conversely, this may help you appreciate why something you thought was overpriced was actually quite reasonable.

In no particular order of importance;

Size

Mineral pricing is assigned based on quality, but organized into tiers based on size. For example, this means there are different price rates for a two inch crystal point versus a four inch point of equal quality.

A big size can be a bit blinding to new collectors, but size isn’t everything… 'big' doesn't automatically mean it should be expensive. The larger you go, typically the harder it is to come by clean, well-formed, high quality specimens. A small museum-quality specimen can be worth many times that of one that is large but industrial-grade.

Color

People are basic animals attracted to vibrant, colorful minerals. That's how we ended up with a market for geodes dyed fluorescent pink. Plenty of minerals are just some shade of brown, tan, beige, cream, sandy, taupe, umber, buff, khaki, or off-white. Having any (natural) color can make a specimen more valuable. 

Minerals that display deep, saturated—but not too dark!—color will be more valuable than those with weak color. A specimen will also be worth more when it displays unusual color, like when something that is typically red has a rare blue form.

Clarity

Minerals can exhibit a range of clarities, some the proverbial 'crystal clear' and others filled with inclusions. In gemology the terms transparent, translucent, and opaque are used to describe the transparency of material, with semitransparent and semitranslucent falling in between. As material becomes more opaque, less light is able to travel through it and the light will be more distorted.

Some minerals can only be opaque, but otherwise the general rule is that more translucent will be more valuable because it shows bright color and reflections. With gemmy minerals like emerald, heavily included material loses clarity, depth of color, sparkle, and general appeal. 

Inclusions

Inclusions are natural imperfections inside the mineral, such as small crystals and fractures. As mentioned above, inclusions can be a bad thing: the basic rule is that more heavily included material will be worth less than material with greater clarity. This is in part because of appearance, but also because heavily included material can be more vulnerable to chipping or breaking, especially if hit on existing natural fractures.

Inclusions can also be a good thing, giving many types of mineral their distinct appearance and character—and value! Garden quartz is technically quartz with elaborate chlorite inclusions; rutilated quartz is quartz included with needles of rutile; red quartz is included with fine red hematite giving the crystals an even red coloration. Gems-inclusion.com is a cool resource to learn more about the fascinating world of inclusions.

Sparkle and luster

Luster is the technical term describing how light reflects off a surface. In gemology and mineralogy there are technical terms to describe a mineral’s surface luster, including metallic, adamantine (diamond-like), vitreous (glass-like), silky, greasy, pearly, and dull. Different lusters are characteristic of different materials, with selenite appearing silky, pyrite metallic, and sandstone dull.

Value will depend on how well a mineral displays its luster. Pyrite that oxidizes and becomes dull is less valuable than shiny metallic material. Quartz crystals with patchy or dull luster are less valuable than ones with an attractive silky luster, or a clean vitreous surface.

Minerals with druzy are also popular. Druzy is a layer of fine crystals which, when well-formed, glitters due to the countless tiny crystal faces reflecting light.

Phenomena

Does it do anything? Specimens that display strong fluorescence, phosphorescence, or other optical effects will typically be more valuable. "Optical effects" are referred to as "phenomena" in gemology, and include things like:

• Cat's eye effect ("chatoyancy") characteristic of tiger's eye
• Star effect ("asterism") found in corundum/sapphire
• Iridescence, ("labradorescence") like labradorite
• Play-of-color, as seen in opal
• Color-change minerals such as alexandrite
• Glitter ("aventurescence") when a mineral has reflective platelet inclusions, like aventurine quartz.
• Adularescence is what gives moonstone an appearance like milky moonlight glowing from within.

Because these unique properties are sought-after, there are many inexpensive synthetics and simulants in the gemstone market; opalite (glass) is often sold as moonstone. If the price seems way too good to be true, it probably is.

Pattern and composition

This one is a bit subjective, but to quote Justice Stewart, I know it when I see it. The pattern in agates, jaspers, and rhyolite can be better-formed in some material than others, and unique eye-catching patterns can fetch higher prices. Similarly, a mineral specimen can look like an unappealing jumble of a few types of minerals. The same minerals in another specimen can be arranged in a dramatic sculptural composition that would be valued much higher.

That's why I have a hard time not providing pick-your-own options even for cheap materials! Each piece can express a different style and personality.

Intactness

A crystal or mineral specimen is worth more if it is complete and intact. For example, a mineral cluster with broken and partial crystals is considered lower quality than one with complete crystals.

It is normal for the base, back, or bottom of a specimen to be broken or "raw" where the piece was removed from the matrix. This does not devalue the specimen (unless poorly done), but it can make "floaters" more valuable. A floater is a crystal that has typically formed in a soft matrix, such as clay, and can be removed without having any markings on the piece indicating it was attached to matrix—as if it formed floating, unattached to anything.

Carving and polishing

Carvings use relatively inexpensive and abundant materials like soapstone, quartz, and calcite, and lower-quality material that was not suitable for sale as a specimen. Polishing surfaces of a mineral specimen devalues it—for example, it is common to see quartz points with polished faces. While this is… shiny… it polishes away the natural surface growth features and devalues the piece for mineral collectors.

The exception is when polishing is key to revealing the mineral's color and pattern. Chalcedonies, jaspers, and rhyolites are typically polished to best display their form; labradorite isn't much to look at without polishing. Polishing also allows you to more clearly see inside materials with interesting inclusions: garden quartz is typically sold polished, and rutilated quartz makes for a beautiful polished spheres and jewelry. Sometimes vendors take a half measure and polish a "window" on a specimen while leaving the rest natural.

Additional factors: treatments and repairs

Natural, unaltered material will typically be more valuable than material that has been repaired, composed, dyed, heat-treated, aqua aura-ed, or in any other way “enhanced” (treat that as a euphemism for "altered" in the industry!).

I avoid purchasing altered or treated materials for inventory, with some exceptions. I will always disclose this when I am aware of it; if you spot something I missed please let me know at PrettyUglyThingsAZ@gmail.com.

Me

As a long-time amateur collector of minerals, I try to price items reasonably. As a small business I may not be able to offer rock-bottom prices (heh), but aim to offer the same kind of pricing I would want to find when I'm shopping. 

Time and growing interest in this project will help bring better deals with scales of economy. It's hard not to sound like a used car salesman saying "when we save, the savings are passed on to you!" but I'd feel skeevy about marking things up just because I can. When I can get it cheaper, you'll get it cheaper!