This page brings together 20 minerals that start with the letter I, running alphabetically from “Ilmenite” to “Iozite.” These minerals range from common clays and ices to rare metallic ores and gem-quality crystals. Some are mined for the metals they contain, like titanium or boron, while others are valued by collectors or cut into colorful gemstones. A few are mostly of scientific interest, showing up in meteorites, volcanic rocks, or industrial settings.
Minerals are naturally occurring solid substances with a defined chemical makeup and an orderly crystal structure. People have relied on them for thousands of years, shaping everything from ancient tools to modern electronics. The Vikings even used a blue mineral called “Iolite” as a navigation aid, viewing the sky through it to locate the sun on cloudy days.
Below you’ll find the table with the mineral names and descriptions.
Mineral: This gives you the name of each mineral, listed in alphabetical order so you can quickly scan the list and find the one you’re looking for.
Description: This offers a short, plain explanation of what each mineral is, where it forms, and what makes it useful or interesting to know about.
Minerals
Mineral
Ilmenite
Illite
Idocrase
Iolite
Idrialite
Inderite
Iodargyrite
Iron
Iridium
Inesite
Indialite
Imiterite
Ianthinite
Ilvaite
Ice
Iranite
Inyoite
Ixiolite
Ilsemannite
Iozite
Descriptions
Ilmenite
A black, iron-titanium oxide mineral and the most important ore of titanium. It is often found in igneous rocks and beach sands, and is weakly magnetic.
Illite
A common clay mineral belonging to the mica group. It forms from the weathering of feldspar and other silicates, and is found in many soils and sedimentary rocks.
Idocrase
Also known as vesuvianite, this is a green, brown, or yellow silicate mineral. It forms in metamorphosed limestone and is occasionally cut as a gemstone.
Iolite
A blue to violet gem variety of the mineral cordierite, prized for showing different colors when viewed from different angles. It was reputedly used by Vikings as a navigation aid.
Idrialite
A rare organic mineral made of hydrocarbons, often found associated with mercury deposits. It is soft, greenish-yellow, and named after the Idrija mine in Slovenia.
Inderite
A soft, white to pinkish borate mineral that forms in evaporite deposits. It is a minor source of boron and was first described from the Inder Lake region in Kazakhstan.
Iodargyrite
A rare silver iodide mineral, typically yellow to greenish and quite soft. It forms in the oxidized zones of silver deposits in arid climates.
Iron
A common metallic element that occurs natively as a mineral, though rarely in pure form on Earth’s surface. Native iron is mostly found in meteorites and some basalts.
Iridium
A very dense, silvery-white precious metal that occurs as a rare native mineral, usually alloyed with platinum or osmium. It is extremely corrosion-resistant.
Inesite
A pink to rose-red silicate mineral that forms attractive bladed or fibrous crystals. It is sought by collectors and occurs in hydrothermal ore veins.
Indialite
A high-temperature form of cordierite, a magnesium aluminum silicate. It is rare and typically forms in burned coal seams or certain volcanic rocks.
Imiterite
A rare silver mercury sulfide mineral, gray in color, named after the Imiter mine in Morocco. It forms in hydrothermal silver deposits.
Ianthinite
A rare, dark violet uranium oxide mineral that is highly unstable and oxidizes readily in air. It forms as an alteration product of uraninite.
Ilvaite
A black, iron-rich silicate mineral that forms striking prismatic crystals. It occurs in metamorphic zones, often associated with iron and zinc ores.
Ice
The solid crystalline form of water, recognized as a mineral when naturally occurring. It forms hexagonal crystals and is the most abundant solid mineral on Earth’s surface.
Iranite
A rare lead chromate silicate mineral, usually saffron-yellow to orange. It forms in the oxidized zones of lead deposits and was first described from Iran.
Inyoite
A colorless to white borate mineral that forms in evaporite and borax deposits. It was named after Inyo County, California, and turns opaque white on dehydration.
Ixiolite
A dark, heavy oxide mineral containing tantalum, niobium, and tin. It is a minor ore source and is related to the columbite-tantalite group.
Ilsemannite
A dark blue molybdenum oxide mineral that forms as a powdery alteration of other molybdenum minerals. It is soft and easily smeared.
Iozite
An obsolete name for wüstite, an iron oxide mineral that is rare in nature. It forms under low-oxygen conditions and is mostly known from industrial and meteoritic settings.
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