Chalcedony vs Opal: What Are They, And What’s The Difference?

Chalcedony and opal are two stones having distinct chemical and physical properties.

Let’s learn about them both.

Chalcedony vs Opal (EXPLAINED)

Opal is mineral silica, which is of a noncrystalline form, while chalcedony is a microcrystalline form of quartz. 

Both of them are gemstones and have many varieties in their type, form, and pattern.

These stones were used in antiquity and also refer as a birthstone to various zodiac signs.

The stones have distinct types and forms.

What are Opals?

Opal is a rare stone that comprises 30% water and has a hardness from 6.0 to 6.5 on the scale as compared to quartz.

Opals have an ancient history as they are approximately or up to many years, approximately 65 million to some 145 million years old.

They are seen in the deepest layer of rock where dinosaurs used to roam around the earth.

Opals tend to be found near the earth’s surface in the area where hot water streams used to flow.

The minerals of the soil come out under the surface of the soil and, gradually covered for centuries, the cavities are made in the bedrock.

Where are Opals are found?

Southern Australia owns more than 90% of the world’s best quality diamond Opals.

Despite the fact, they can be found in other regions of the world, which include Brazil, Ethiopia, Nevada, and Czechoslovakia.

However, Australia also owns relatively all the dark Opals.

To characterize opal in layman terms, it could be a tough stone mineraloid that has mineral characteristics but is not one of them) that is covered with the chemical silicone dioxide, which appears from the cracks in the tainted vegetation, wood and bones of the dead.

In the language of science, the opal is known as SiO.nH2O.   

Colors Opals Are Available In

Not like all other accessories, the opal comes in many assortments that are white, blue, ruddy, dark, and, of course, colorless.

The most fascinating thing about this stone is that it shows all its colors from obstruction and the diffraction through which the light is hitting it.

In contrast to that, the glittering multicolor of the opal will change when seen from another angle.

What Are The Varieties Opal Comprises?

There are mainly two types of opal, which are precious and common.

Precious Opals show characteristics that are also known as “play of color” that are uncommon and rare comparatively.

Other types of opal that are known as common Opals are gloomy and worthless.

Common Opals do not show the play of colors always.

It is known as potch when the precious and common Opals are found in terms of each other.

The common or potch opal is approximately 95% mined out and turns out to be single colored.

There are a few colors that are 5% remaining. The gemstones that originated are sedimentary, including opals.

6 to 10 % of water is consumed by the opals, which is basically the leftover from the ocean.

In 1863, some of the very rare and valuable pieces of opal were found by gold panners in Australia.

However, the overall steady commercial opal was found in Australia.

See also: Can Opal Scratch Glass?

How Is Opal Different From Chalcedony?

As compared to opal, chalcedony is a hard rock made of microcrystalline quartz.

It contains two different types, which include agate and jasper.

Chalcedony is believed to be a very strong, hard material of rocks.

Inevitably, this might be the reason ancient people used to make their weapons with the stones of chalcedony.

The hardness of chalcedony is approximately 7 according to the Mohs hardness scale.

 In comparing Opal and Chalcedony, you’ll see that each has distinctive properties and patterns.

The opal is a softer rock while the chalcedony is a harder one and breaks with a conchoidal fracture, which means that the broken pieces of this rock are smoother and pointedly curved.

These broken pieces of chalcedony have a waxy, dull luster, which is because of the bright vitreous luster.

In What Colors Is Chalcedony Available?

Chalcedony happens in a wide array of colors.

It is commonly white, grey, ruddy, brown, orange, yellow, and dark, but it can happen in any color.

It can moreover be united or have tuft, dendritic, blotched, overgrown, or other colorful structures within.

With its colorful appearance, capacity to acknowledge shining cleanliness, durability to outlive the tumbler, and prepared accessibility.

Chalcedony is the culminating fabric for making tumbled stones.

What Are The Two Prominent Types Of Chalcedony?

There are two distinct types of chalcedony that include agate and jasper.

Both of the varieties of chalcedony are separate in nature and also show different properties.

What is Agate?

Agate is a semi-transparent to translucent material which distorted light passes through.

How is Agate formed?

Almost many agates generate in the areas of volcanic eruption, where water is dissolved in silica and in the cavities of igneous rocks.

In spite of the fact that agates ordinarily are shaped in volcanic rocks such as andesite, basalt, and rhyolite, they could, also, shape sedimentary rocks such as limestone.

All of these sorts of rocks are more vulnerable to weathering than agate.

So when the rocks are broken by weathering, the strong agates stay.

This is eventually the reason why agate rocks are frequently found in stream valleys that cut through fine-grained molten rocks or limestone.

 Is Jasper A Type Of Chalcedony?

Jasper is an opaque type of chalcedony, in which the light doesn’t pass through. Jasper has enough amounts of impurities that it makes it look opaque.

How Is Jasper Formed?

When the fine particulate materials are covered or cemented by silica, jasper is formed.

They are also formed by volcanic ash.

Wrap Up

Opal and Chalcedony share the same nature but different properties, which are strength, color, and nature, which are exclusively different from each other.

However, the uncrystallized form of quartz is known as chalcedony, while the hydrated version of silica is opal.

Both of the rocks are composed of quartz as quartz is the foremost mineral of sand and sandstone.

Interested in learning more about opals? Check out:

Chalcedony vs Opal