Rocks and Minerals That Look Like Glass

There are many rocks and minerals on this earth that express different physical properties.  Some of those physical properties will make rocks and minerals look like glass.  In this article I want to go over some great examples of rocks and minerals that look like glass.

Some of the best known rocks and minerals that look like glass are diamond, clear quartz, topaz, amber, amethyst, citrine, sapphire, ruby, dioptase, obsidian, gypsum, and garnets.  There are many other different rocks and minerals that can also look like glass.

Black and Clear Rocks and Minerals

There are a few well known black rocks and minerals that look like glass.  Those are black tourmaline, onyx, quartz, garnets, and obsidian.  These rocks and minerals have high luster and somewhat of a black transparency that make them look like glass. 

There are many clear rocks and minerals that look like glass.  Some of the popular ones are topaz, diamond, quartz, and gypsum.  These clear rocks look like glass because they not only have a high luster, but a very high transparency.

Examples of Rocks and Minerals That Look Like Glass

Topaz

Topaz is a great example of a mineral that can look like glass.  It can have such a high transparency that you can clearly see right through it.  What helps distinguish topaz from glass is the crystal structure that topaz has.

This mineral just looks like a natural crystal by default as it has nice clear edges and a termination that typically ends in a rounded out point.  Topaz is naturally a yellowish brown color, however when sitting out in the sun it will bleach out that color to a clear crystal.

For more detailed information on Topaz you can click over to my article “All About Topaz” 

Obsidian

Obsidian is the only one of these examples that is considered an actual rock and not a mineral.  Obsidian is quite a special case from all other examples when being compared to glass.  This rocks great fame comes from it being considered nature’s glass.

Obsidian looks and behaves like glass more so than any other rock or mineral.  It is so high in silica content some like to classify it as a mineraloid rather than just a rock.  The main reason it is a rock or mineraloid is it really has no crystalline structure. 

For more detailed information on Obsidian you can click over to my article “All About Obsidian” 

Quartz

Quartz is a very common mineral on our earth.  When this mineral comes as a more clear form, it often looks like glass.  Clear quartz can have some very high transparency and when compared to a piece of glass, it can be difficult to tell the difference.

Quartz comes in many different varieties.  Many of these different varieties will often look like glass.

Amethyst

This very popular mineral can look like glass and in fact is part of the quartz family.  Amethyst is typically amethyst because it’s purple.  It is not improbable to find a loose piece of amethyst that may look a little a beaten up piece of glass.

Though it might be purple, amethyst can easily look like glass.  A purple glass of course.  Like quartz, amethyst will have sharp edges and have a termination on one side to help distinguish it.

For more detailed information on Amethyst you can click over to my article “All About Amethyst” 

Gypsum

Gypsum is quite a special mineral and can at times look like glass.  This mineral takes on a few different forms and I would venture to say that a couple of those forms can make some think of glass.

Kids can really get into collecting this mineral and you may have even heard of a gypsum wand.  Gypsum can take form in a couple of very popular ways.  Perhaps it having some ability to look like glass has helped with that. 

If you don’t know much about Gypsum, yes, I have written a great article talking about this mineral as well “All About Gypsum”.   

Garnet

Garnets can very often look like glass.  Their shape may not always contain defined sides and edges and they often can reflect light and have some transparency.  This can lead many to think they have a piece of glass in their hand.

Garnets to come in many colors though.  If you find one it might express some uniqueness in color. If you are lucky to find a nice one, it will have some defined sides and edges that make it look like a gem.

Sapphire

Raw sapphires are perhaps one of the most difficult minerals to tell apart from glass.  They really look like a piece of glass.  Sapphires look like glass more so than other minerals due to their lack of visual structure. 

You do not typically see nice clear or smooth edges with a sapphire when found. However, when sapphires are broken, you will see more of a glassy type surface. And when these minerals are cut, they really look great when those rough edges are smoothed out.

Some sapphires are blue, green, yellow, and red. This might make it easier to tell if it is something other than glass. As for the clear ones though, good luck there.

Why do Rocks and Minerals Look Like Glass?

The main reasons that rocks and minerals look like glass are they will typically have some sort of transparency.  The next reason for rocks and minerals looking like glass is they have a great molecular structure.  This gives them a high reflective surface or what is known as luster.

Is it Glass or is it Rock?

A good way to tell if you have a rock or glass is to see if you can find any bubbles within it.  If you see tiny bubbles, you likely have glass.  You can also at times tell the difference by the visual structure of the specimen.

Many rocks and minerals have a particular natural crystalline structure.  Small pieces of glass, when broken, are typically not structured.  Glass will often have jagged pieces and stress lines along the break.

If you are in an area that is known for a certain mineral that looks like glass, then expect what you might find on the ground to be that mineral.