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Red and Pink Minerals

The most common and significant ones

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Red and pink minerals are eye-catching because the human eye is especially sensitive to those colors. This list is primarily minerals that form crystals, or at least solid grains, for which red or pink is the default color in natural occurrences. (Earthy red minerals aren't on this list; they can be any of several different secondary minerals that require special tests and geologic observations to identify.) Here are some rules of thumb about red minerals: 99 times out of 100 a deep red transparent mineral is garnet, and 99 times out of 100 a red or orange sedimentary rock owes its color to microscopic grains of the iron oxide minerals hematite and goethite. And a transparent mineral that's pale red is a clear mineral that owes its color to impurities. The same is true of all clear red gemstones like ruby.

Consider the color of a reddish mineral carefully, in good light. Red grades into yellow, gold and brown, and while a mineral may show a red highlight, that should not determine the overall color. Also ascertain the mineral's luster on a fresh surface as well as its hardness. And figure out the rock type—igneous, sedimentary or metamorphic—to the best of your ability (start with "How to Look at a Rock").

Alkali Feldspar

Geology Guide photo
This very common mineral can be pink or sometimes a light brick-red, but usually it is closer to buff or white. Put it this way: a rock-forming mineral with a pink or pinkish color is almost certainly feldspar. Luster pearly to glassy; hardness 6.

Chalcedony

Geology Guide photo
Chalcedony is the noncrystalline form of quartz, found exclusively in sedimentary settings and as a secondary mineral in igneous rocks. Usually milky to clear, it takes on red and red-brown colors from iron impurities, and it forms the gemstones agate and carnelian. Luster waxy; hardness 6.5 to 7.

Cinnabar

Geology Guide photo
Cinnabar is a mercury sulfide that occurs exclusively in areas of high-temperature mineralization. If that's where you are, look for its lipstick-red color, once prized for cosmetic use. Its color also edges toward metallic and black, but it always has a bright red streak. Luster waxy to submetallic; hardness 2.5.

Cuprite

Courtesy Sandra Powers
Cuprite is found as films and crusts in the lower weathered zone of copper ore deposits. When its crystals are well formed, they are a deep red, but in films or mixtures the color may range toward brown or purple. Luster metallic to glassy; hardness 3.5 to 4.

Eudialyte

Wikimedia Commons
This oddball silicate mineral is quite uncommon in nature, being restricted to bodies of coarse-grained nepheline syenite. But its peculiar raspberry to brick red color makes it a staple in rock shops. It can also be brown. Luster dull; hardness 5 to 6.

Garnet

Geology Guide photo
The common garnets consist of six species, three green calcium garnets ("ugrandite") and three red aluminum garnets ("pyralspite"). Of the pyralspites, pyrope is yellowish red to ruby red, almandine is deep red to purplish and spessartine is red-brown to yellow-brown. The ugrandites are usually green, but two of them—grossular and andradite—may be red. Almandine is by far the most common in rocks. All of the garnets have the same crystal shape, a round form with 12 or 24 sides. Luster glassy; hardness 7 to 7.5.

Rhodochrosite

Geology Guide photo
Also known as raspberry spar, rhodochrosite is a carbonate mineral that will bubble gently in hydrochloric acid. It typically occurs in veins associated with copper and lead ores, and rarely in pegmatites where it may be gray or brown. Only rose quartz might be confused with it, but the color is stronger and warmer and the hardness much lower. Luster glassy to pearly; hardness 3.5 to 4.

Rhodonite

Wikimedia Commons
Rhodonite is far more common in rock shops than it is in the wild. You'll find this manganese pyroxenoid mineral only in metamorphic rocks rich in manganese. It's usually massive in habit rather than crystalline and has a slightly purplish-pink color. Luster glassy; hardness 5.5 to 6.

Rose Quartz

Wikimedia Commons
Quartz is everywhere but its pink variety, rose quartz, is much scarcer, being limited to pegmatites. The color ranges from the sheerest pink to a rosy pink and is often mottled. As with all quartz, its poor cleavage and typical hardness and luster define it. Unlike most quartz, rose quartz does not form crystals except in a handful of places, making them pricy collectibles. Luster glassy; hardness 7.

Rutile

Courtesy Graeme Churchard under Creative Commons
Rutile's name means "dark red" in Latin, although in rocks it is often black. Its crystals may be thin, striated needles or thin plates, occurring in coarse-grained igneous and metamorphic rocks. Its streak is light brown. Luster metallic to adamantine; hardness 6 to 6.5.

Other Red or Pink Minerals

Dolomite — Geology Guide photo
Other truly red minerals (crocoite, greenockite, microlite, realgar/orpiment, vanadinite, zincite) are rare in nature, but common in well-stocked rock shops. Many minerals that are usually brown (andalusite, cassiterite, corundum, sphalerite, titanite) or green (apatite, serpentine) or other colors (alunite, dolomite, fluorite, scapolite, smithsonite, spinel) can occur in red or pink shades.

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