So You Found a Galaxy Stone…. What is it?

Galaxy Stones are the trade name (or commercial name) given to a type of rock but what is amygdaloidal Vesicular basalt and why do you want one?

This Ayrshire galaxy stone has mostly calcite vugs.

Galaxy stones are really fun. We actually started collecting them completely by accident. We picked one up, asked the internet what it was, and had someone on TikTok offer to buy it. Since then, we always pick it up wherever we see it.

What Are Galaxy Stones?

Galaxy stone is the commercial name we give to a rock called amygdaloidal vesicular basalt. This sounds like a lot but we will break it down in a minute. First, we need to have a brief chat about trade names.

Trade names for crystals and mineral specimens are almost like nicknames. They are given to types of rock and crystal to make them easier to sell. Here are a few good examples:

• Spirit Quartz – is just very pale amethyst drusy (druzy if you are American)

• Lemurian Quartz – is just quartz with striations, which are natural growth lines.

• Citrine which is actually burnt amethyst.

• Opalite – glass which mimics opal but is still just glass.

• Strawberry/Honey/Golden Healer Quartz – all just quartz with different iron oxides in them.

Our thoughts on trade names for stones? As long as they don’t do any harm, then we happily use them. We also use the to hit the keywords we need to hit to become acquainted with the people who are seeking these rocks out.

However, when that trade name starts to invoke a legacy of lies instead of just being a cute nickname – like with lemurian and golden healer quartz – it becomes a problem. We rate galaxy stones as fine to give a nickname to because we are not using that nickname to trick anyone.

Back to the basalt.

This chonker galaxy stone is the length of my hand and weighs roughly 900g.

What is Basalt?

Basalt on its own is the cooled down rocks left behind after volcanic activity. Basalt exists in regions which were once volcanic, and sometimes in places which are still volcanic. It usually cools as a sort of flow and spread style blanket. However, it can also for really cool shapes. The hexagonal basalt columns of Fingal’s Cave on Staffa and the Giant’s Causeway in Ireland.

At its most basic, basalt is lava which turned into rock.

Amygdaloidal Basalt

“Amygdaloidal” is a term which refers to the lava-turned-rock itself. This basalt was formed when lava cooled slowly, allowing for trapped gases to escape as bubbles rising up from under the blanket.

Because of these gas bubbles and because the lava has cooled slowly, these gas bubbles have become trapped in the stone. These are sometimes called amygdales. And another name for amygdales is “vesicles.”

Vesicular Basalt

Vesicular basalt is basalt which contains amygdales, or vesicles, which other minerals have gradually filtered into and filled in. The vesicles are holes, also called vugs, and these vugs fill with sediment over time.

Put it All Together and you get Galaxy Stones!

So you start with a magma which erupts into lava via volcano. The lava cools slowly because the climate is warm, leaving bubbles of gas to ris up through it. This lava becomes basalt when it hardens, trapping those air bubbles. The air bubbles then fill in with other sedimentary minerals over time.

So although the basalt is an igneous rock, the stuff in the vugs which looks like little planets is sedimentary.

What is in the Vugs?

That leads us to what you find in those vugs. That depends largely upon where you live and what the local mineralisation is like.

In the old lava beds of Ayrshire, you find mainly calcite, pink calcite, quartz, and chalcedony. The chalcedony down in Ayrhsire tends towards pinks and greys. Up near Queensferry that pink and grey becomes predominantly carnelian. If you go up the Fife and Angus way, you will find the vugs contain lots of greens as opposed to pinks. Chlorite and iron oxides add to the green.

If you go far, far, far north, you might find thompsonite in your vugs.

Why Are They Called Galaxy Stones?

Amygdaloidal vesicular basalt is referred to as “galaxy stone” because the basalt is usually black or dark in colour, while the little vugs of colour look like planets. They are often round. The whole rock looks like a night sky, especially when polished.

Where Do You Find Galaxy Stones?

We sort of gave this away! If you find nodules of quartz, jasper, chalcedony, or agate, then you are in the right place to find a galaxy stone. Look for old volcanic areas and places where you find agate.

In Scotland you will find galaxy stones in Ayrshire, in Fife, in Angus, and even on the Isle of Mull, as Louisa the Scottish Geologist can show you in this video she made. You should also check out the Scottish Agate pages as there is a lot of crossover.

Where Can You Buy Galaxy Stones?

Of course, rockhounding isn’t for everyone. If you have mobility issues and can’t get out, don’t have the eye for it, or just can’t be bothered, then you can buy your galaxy stones from The Stone Circle. We sell them here in small and medium sizes, or on Etsy as small, medium, or large rocks.