Terms

🪨 Color zoning When a mineral has distinct banding or sections of color. Color zoning results when shifts occur during the mineral's growth process, changing the conditions or the color-causing trace elements available. Common examples include "watermelon" pink and green tourmaline, and the hexagonal dark and desaturated blue banding sometimes visible in sapphire (corundum). The purple fluorite at left displays color zoning that displays its cubic growth form.

🪲 Conglobate Term for an animal rolling up into a ball to defend itself, so that its hard (or spiky!) outer shell deters predators. Conglobation is the isopod's defense mechanism. This is alternatively (and more accurately) called volvation.

🪨 Coprolite Fossilized feces, colloquially called "dino dung" though specimens can be attributed to any number of prehistoric species.

🌱 Etiolate Meaning "to enfeeble," etiolation is when plants grown long slender because they are reaching for light. This commonly occurs to cacti and succulents kept as indoor plants without adequate lighting. Etiolation weakens the plant because it does not form a wide, strong base, and many cacti and succulents cannot recover from etiolation—meaning they will always have pinchy elongated sections.

🪨 Feather Feather is the technical term used in gemology and mineralogy to describe natural fracturing as an inclusion inside a mineral. Feathers are common in some minerals, and minerals with feathers can be handled normally without risk to the piece. The danger applies when set in jewelry: pressure applied in the wrong place during the setting process can worsen fractures, and jewelry gets knocked around during wear.

🪨 Ferruginous (ferric, ferrous) Technical descriptive term for minerals colored by small iron-oxide inclusions, a class of minerals including hematite and magnetite. A deep brick red color is characteristic, but color can be lighter, bright orange, or more brown. Iron-based inclusions are also commonly black. Ferruginous quartz is an example.

🪨 Fluoresce(nce) A fluorescent mineral will emit light ("glow") when exposed to UV light. This can open up a whole new dimension of your collection: minerals can react with different vibrancy and colors under different UV wavelengths. 365nm UV light is a favorite and mineral dealers will often have 365nm flashlights available at mineral shows because it will fluoresce quite a few minerals. Colorless hyalite fluorescing green under 365nm UV light:

🪨 Fossil Evidence of remains of prehistoric life forms preserved in rock. This can mean the life form, or a piece of it, became rock or mineral through a process called petrification where minerals slowly replace the organic material. There are many types of fossils that form through different means in different rock types.

Trace fossil 'Trace' as in a trace left behind by a life form has been preserved rather than the life form itself. Dinosaur footprints are a great example of a trace fossil. Coprolites—fossilized feces—are also trace fossils.

Resin/amber Fossilized plant resin is known as "amber." The resin has hardened and stabilized in the fossilization process. Amber can be highly sought after when it has entrapped and preserved life forms such as plants and insects.

🪲 Frass 'Frass' is the technical term for insect droppings. Isopod frass is distinctively rectangular and flat in shape. I refer to pooping isopods as "ticket dispensers" because you will sometimes see them use their back legs to grab and discard the little rectangles of frass. I literally used a graphic of confetti to make this helpful diagram:

🪨 Geode A typical geode is a round hollow mineral specimen, with the outside appearing like a rock and the inside lined with crystals. Geodes most commonly form in pockets left by bubbles in volcanic rock, and can have quite irregular blobby or elongated shapes. They can also grow enough crystals to completely fill the cavity, so 'hollow' is not a requirement. Quartz is the most abundant geode-forming mineral, producing a range of distinct varieties ranging in size from pocket pieces to large enough to walk inside.

🌱 Glochid Small, fine cactus spines. Glochids are infamous for growing in dense clusters and easily detaching from the cactus. Large numbers of near-invisible spines will stick into your skin, clothing, or ANYTHING with the lightest brush. I have had to throw away gardening gloves.

🪲 Gravid Your invertebrate is pregnant! Instead of laying eggs, female isopods form a pouch on their belly (the marsupium) where the babies will grow until large enough they hatch out of the marsupium.

🪨 Habit A mineral's 'habit' refers to common shapes crystals will grow in as a result of its crystal structure and conditions. For example fluorite has a cubic habit, commonly growing in distinct cubes. A mineral's value is in part based on how well it displays its crystal habit. How common or unusual that crystal habit is will also play a factor.

🪲 Instar Term for the stages of development in insects. They are distinctly defined by molts, as the insect has developed into a new growth phase with each shed. The first instar refers to the insect before its first molt, the second instar is after the first molt, and so on.

🌱 Intergeneric Hybrid between two genera, rather than between species.

🪨 Inclusions A mineral can trap foreign items in a chamber inside it as it grows: other crystals, liquids, even gasses.* These are called 'inclusions.' Fractures, called feathers in gemology, are also a common natural imperfection categorized as an inclusion. Inclusions can be a bad thing: with gemmy minerals like emerald, heavily included material loses clarity, depth of color, sparkle, and general appeal. They are considered lower quality. Heavily included material can also be more vulnerable to breaking, especially if hit on existing natural fractures. Other types of inclusions can give a mineral its character and make it more valuable, like garden quartz with elaborate chlorite inclusions, or rutilated quartz included with needles of rutile.

The most common type of inclusion is a single-phase inclusion, meaning it is either a liquid, a solid, or gas. Solid is most common; in fact it’s what gives some minerals like red quartz their coloration.

Two-phase inclusion an inclusion that includes two of three phases. Common examples are a pocket of fluid with a bubble or crystal in it.

Three-phase inclusion an inclusion that includes all three phases. This commonly means fluid in a cavity, with both a bubble and crystal inside.

Learn more about inclusions from Gems-Inclusions.

* Minerals will NOT trap organic materials like insects or leaves though, that is only geologically feasible with amber and fossils!

🪨 Jasper Jasper is basically a more impure version of chalcedony, the cryptocrystalline version of quartz, that is opaque or near-opaque. The term 'jasper' has historically been used for material with warm tones of red and brown, but there are jaspers of every color. 'Jasper' is also a common misnomer in the trade, frequently used for other colorful opaque minerals.

🪨 Leaverite That’s just a rock. You better leave ‘er right there. A favorite joke among geologist and rockhounds, used on unwitting noobs who think they've found something more interesting than a simple rock.

🪨 Luster The nature of how light reflects off a mineral’s surface. High luster means something is very shiny or reflective. In gemology and mineralogy there are technical terms to describe a mineral’s surface luster, including metallic, adamantine (diamond-like), vitreous (glass-like), silky, and dull.

🪲 Manca(e) Baby isopod doo doo do-doo do-doo. Mancae are the first instar in isopods after the larvae hatch from the marsupium. They typically do not have the coloration of adults yet and look like little white rice grains.

🪲 Marsupium Instead of laying eggs, female isopods form a pouch on their belly called the marsupium. The larva (babies) grow there until large enough they hatch out of the marsupium as mancae.

🪨 Matrix The surrounding material a mineral has grown embedded within, also referred to as its host rock. The term 'matrix' is usually reserved for rock that is not of itself a mineral of particular interest or value. It is typical for specimens to simply be identified like "calcite on matrix" with no additional detail about the matrix.

 🌱 NOID "no ID" meaning a plant is of unknown identification. The term can be applied loosely.

🪨 Octahedra(-al,-on) A crystal habit that is like two four-sided pyramids back-to-back, creating an 8-sided bipyramid. Octahedral crystals are found in minerals of the cubic family including spinel, diamonds, and fluorite (commonly cleaved). Image credit for the spinel and diamond to Robert Lavinsky, iRocks.com

🪨 Orbicular Round 'orb-' or eyeball-like patterns in minerals, often showing multiple rings of color. These are alternatively referred to as spherulites because they are composed of dense radial needle-like growth from a point to create spheres with banded color (hence "spher"ulite). Spherulites are typically crystalized feldspar forming within volcanic igneous quartz-based rock. 

🪨 Palm stone A polished oval rock that fits well in the palm and has good hand-feel (that’s my word, I’m coining it). A palm stone is larger and heftier than a worry stone, but still a good size for carrying around in a pocket.

🪨 Phenomena Interesting optical effects in gems and minerals are called "phenomena." This includes cat's eye effect, stars in minerals, iridescence, and color change stones.

🪨 Phosphoresce(nce) This refers to the “glow in the dark” effect some minerals exhibit when exposed to UV light, where they continue to emit light (glow) for a short period after you turn off the UV light. This glow typically lasts mere seconds, but in rare cases it can be as long as minutes. Calcite and its close relative aragonite often display phosphorescence.

🪨 Picture jasper Trade name for jaspers (also a trade name, indicating) that 

🪲 Poot shoot Like shrimp, isopods have a poop vein down their back that is visible through the translucent exoskeleton of a lot of isopod varieties. This has been colloquially deemed the 'poot shoot.'

🪨 Precipitate In the mineralogical sense, this refers to the process whereby water can precipitate trace minerals from surrounding waters and deposit them onto a surface. The mineral growth is also referred to as the ‘precipitate.’

🪲 Pruinescence The dusty matte appearance insects can have as opposed to being shiny, such as the aptly named Porcellionides pruinosis isopod. Pruinescence is a coating on the exoskeleton and can rub off (similar to the bloom on grapes).

🪨 Pseudomorph A specimen where one mineral has been replaced by another, but the new mineral retains the the form of the original. Pseudomorphs can be quite valuable and collectible depending on their rarity. The phrase "X after Y" should be interpreted to mean a pseudomorph where the specimen is X mineral in the form of the previous mineral, Y. You may see the notation “ps.” used to indicate a pseudomorph on identification cards. 

Polymorph When the same chemical composition can grow in different crystal structures resulting in different minerals. Calcite and aragonite are polymorphs of one another because they are both chemically calcium carbonate. When calcium carbonate grows in a trigonal crystal structure it is calcite, and when it grows in the orthorhombic structure it is aragonite.

Paramorph A pseudomorph of the same chemical composition but different crystal structure, like the polymorph. The difference is this one involves a transformation of an existing mineral example an aragonite crystal transforming into calcite

Epimorph Also known as an incrustation pseudomorph, one mineral grows in a crust on another mineral, then the first mineral dissolves leaving behind a crust in its form but composed of the second mineral. 

🪨 Pseudo-[shape] In reference to a crystal habit, if something is called "pseudo-hexagonal" or "pseudo-cubic" instead of simply hexagonal or cubic, this means it is actually not possible for that crystal system to create that shape. Instead the shape has been created through twinning of multiple crystals that look like a single cubic or hexagonal crystal.

🌱 Pup The name typically used for young offset plants on cacti and succulents. Pups are a genetic clone of the main plant.

🪨 Radial A type of mineral growth formation, when individual crystals radiate out from a center point, like spokes on a bike wheel.

🪲 Sexually dimorphic Dimorphism means there are two different forms of the species; sexually dimorphic means the two forms are displayed according to the sex of the insect. Porcellio species show the most sexual dimorphism in isopods. In Calicos and Lavas, the males are all gray while females are spotted orange and gray. Males of the expansus and bolivari varieties have extra-long uropods (butt spikies).

🪨 Spherulite Spherulites are typically crystalized feldspar inclusions forming within volcanic igneous quartz-based rock. They grow dense needle-like growth radiating out from a point to create a sphere (hence "spher"ulite). Spherulites can appear as clusters of needles or distinct rings of colored banding as in the case of leopardskin jasper, an orbicular spherulite.

🪲 Substrate Substrate is the fancy word for the base soil layer in your terrarium or enclosure; the term can also include the layer of leaf litter and rotting wood on the surface though isopod keepers often discuss them separately. Substrate is the growing medium for plants and home to bioactives like fungi, springtails, and dwarf whites.

🪨 Tabular Refers to a crystal habit that is flat and thin like a tablet of paper.

🪨 Trade name The 'trade name' for a gem or mineral refers to non-scientific naming conventions developed in the industry to identify different materials based on their locale and appearance. For example, 'Herkimer diamond' is a trade name for an especially clear and lustrous form of quartz crystal from the Herkimer region of New York. 

🪨 Transparency Transparency is a combination of how much light gets through the material, and how distorted that light is. The latter can be checked using a 'readability' test. Put the material on top of text. Can you read it, does it look fuzzy, or is it completely obscured?

The technical terms used to describe a mineral's transparency are transparent, translucent, and opaque, as well as semitransparent and semitranslucent which fall between:

🪲 Volvate The technical term for an animal rolling up into a ball to defend itself, so that its hard (or spiky!) outer shell deters predators. Volvation is the isopod's defense mechanism. This is also called conglobation.

🪨 Xenolith A xenolith is a foreign ('xeno-') rock ('-lith') embedded in another rock, typically referring to something embedded in magma/igneous rock before it solidifies. Peridot in basalt is an example of a xenolith.