6 Types of Rocks That Are Yellow (And Where You Can Find Them)

The United States offers a wide variety of rocks and crystals.

Yellow is one of the most popular colors to hunt for when it comes to rocks, even though it is rare to find in nature and is more found at gem shows and shops.

However, if you are lucky enough to find a yellow mineral, it can only be a particular rock or crystal.

The following is a list of the most common yellow stones you’ll find in nature and where you can find them.

6 Types of Rocks That Are Yellow

Amber

A fossilized resin, amber, is formed when volatile constituents are lost through burial in the ground and chemical change occurs.

Despite its wide distribution, the largest deposits of amber occur along the Baltic Sea shore in sands that are 40,000,000 to 60,000,000 years old.

The specific gravity of amber ranges from 1.04 to 1.10, which is slightly heavier than water (1.00).

Depending on the amount and size of air bubbles, amber can appear transparent or cloudy. It often occurs in the color of honey yellow, root-beer brown, and black.

Amber’s hardness ranges from 2-3 on the Mohs scale and has a luster resinous appearance.

If you go rockhounding, you can find isolated pieces of amber in Cenozoic sedimentary rocks.

In the United States, there are large deposits of Amber in Arkansas and New Jersey.

Calcite

Calcite is a rock mineral with a calcium carbonate (CaCO3) chemical formula.

As a result of its ability to be found anywhere in the world, it is known as a universal mineral.

You can find it in sedimentary, metamorphic, and igneous rocks.

Limestone and marble are predominantly composed of calcite.

Diagenesis transforms limestone into a shell, coral, and algal debris, eventually becoming calcite.

When limestone is heated and pressed, it metamorphoses into marble.

Calcite’s cleavage faces can often be found on a broken piece of marble.

Depending on the level of the metamorphic process will determine the size of calcite crystals.

Usually, the higher the level of metamorphism, the larger the calcite crystals will be.

Calcite will have yellowish colors due to iron oxide staining when found near the Earth’s surface.

Calcite has a waxy or glassy luster, with a Mohs hardness of 3.

You can find calcite in Colorado, Illinois, Indiana, Kansas, Missouri, Massachusetts, Nevada, and Tennessee.

Carnotite

Carnotite is a mineral that forms from various uranium-containing minerals while being dissolved and decomposed.

In the United States, it is the most valuable source of uranium.

The material is usually mined from rocks where the water originated underground through sandstones.

It is a fine yellow crystal with a hexagonal habit, some of which resemble minute crystals.

A tiny amount of this substance is found in very shallow depths and mostly comes from groundwaters.

On the Mohs scale, carnotite has a hardness of 2 and a dull luster.

The largest carnotite deposits are in the Colorado Plateau of the United States.

There are also other carnotite deposits in Pennsylvania, South Dakota, and Wyoming.

Gypsum

Gypsum is a sulfate mineral mainly composed of hydrated calcium sulfate.

In Permian and Triassic sedimentary formations, gypsum occurs in extensive beds and other evaporite minerals in saltwater.

Typically, it appears clear when it forms crystals.

However, it can have a yellowish tone due to clay and iron oxide compositions in the formation process.

The only source of gypsum is sedimentary rocks that developed in an evaporitic environment.

On the Mohs scale, gypsum is hardness two and has a glassy luster.

California, Iowa, Nevada, and Texas are the states that produce the most gypsum in the United States.

Quartz

Quartz has a chemical compound of silicon and oxygen.

It is the most abundant mineral on Earth and has several unique properties among all the natural substances.

All temperature ranges are conducive to the growth of quartz, which can be found in igneous, metamorphic, and sedimentary rocks.

Quartz is highly resilient to chemical and mechanical weathering.

The durability of the crystal allows it to form in mountaintops, beaches, rivers, and deserts.

Some quartz specimens are yellow but generally white (milky) or transparent.

Despite agate’s more orange or red appearance, yellow quartz is the most common type of microcrystalline rock.

Citrine is a precise yellow gemstone variety of quartz; the color may grade into amethyst or brown, depending on its grade.

A fine needle-shaped crystal of another mineral provides the cat’s eye quartz with its golden sheen.

Quartz ranks a seven on the Mohs hardness scale and has a vitreous luster.

The best places to find yellow quartz are Arkansas, Arizona, and North Carolina.

Sulfur

The nonmetallic element sulfur, also known as sulphur, belongs to the oxygen group of elements.

It is most commonly found in the pyrite crusts and films that form when pyrite is oxidized in old mine dumps. There are two places in nature where sulfur can be found.

Originally, sulfur was mined from deep sedimentary bodies, but it can now be obtained more cheaply as a petroleum by-product.

Active volcanoes also produce sulfur, which condenses in crystals when a sulfur vapor escapes from the vents called solfataras.

The color of sulfur is pale yellow, and it appears as a brittle solid.

The yellow color may also range from an amber color to a reddish tone depending on its contaminants.

Sulfur has a resinous luster and ranks a two on the Mohs hardness scale.

Wrapping Up

Many rocks are yellow found in mineral shops and shows.

However, most of these minerals are not commonly found yellow in nature, such as gummite or pyrargyrite.

In essence, the six minerals listed above frequently occur in yellow colors.