Crystals
Aquamarine is beryl, Mohs 7.5 to 8, used for courage to speak, calm, clarity. The mineralogy, whether it is safe in water and sunlight, what gets substituted for it, and what a stone can honestly do.
Start with the mineralogy, because most of the bad advice about this stone follows from not knowing it. Aquamarine is beryl. On colour: Iron. The same mineral coloured by chromium is emerald, by manganese is morganite, and clear is goshenite.
Where it comes from: Minas Gerais in Brazil, Pakistan, Nigeria and Madagascar.
| Property | Value |
|---|---|
| Mineral species | Beryl |
| Chemical formula | Be3Al2Si6O18 |
| Mohs hardness | 7.5 to 8 |
| Crystal system | Hexagonal |
| Chakra | Throat |
| Usually linked to | Pisces and Aquarius, and to Neptune |
Hardness matters more than it sounds. The Mohs scale runs from talc at 1 to diamond at 10, and anything below about 5.5 can be scratched by ordinary window glass or by the quartz dust in everyday grit. At 7.5 to 8, aquamarine is hard enough to handle daily wear without much trouble, though it will still scratch a softer stone it is stored against.
Used for composure, particularly under pressure and particularly when speaking. It is March's birthstone and the traditional stone of sailors, carried for safe passage, which is the sense the name carries: water of the sea.
In the shorthand most shops and books use, it is a Throat stone, and the three words attached to it most often are courage to speak, calm, clarity.
This is the section that matters, and the one most pages get wrong. Cleansing advice is handed around as though every stone were the same mineral, and it is not. Here is what aquamarine will actually survive.
| Method | Safe? | Why |
|---|---|---|
| Water | Yes | Safe in water. Quartz family stones are hard, non-porous and chemically stable, so a rinse does no harm. |
| Direct sunlight | No | Fades in direct sunlight. The colour loss is permanent and it is faster than most people expect: a sunny windowsill will visibly pale a piece within a season. |
| Salt or salt water | With care | Dry salt is tolerable, though it scratches a polish over time and there is no particular reason to use it. |
| Moonlight | Yes | Harmless to every stone on this list, which is most of why it is the method that suits everything. |
| Smoke, sound or breath | Yes | Nothing physical touches the stone, so nothing can be damaged by it. |
Almost all commercial aquamarine is heat-treated to remove the yellow and leave pure blue, which is standard, stable and accepted in the trade. Blue glass and blue topaz are both sold as aquamarine; topaz is denser and considerably more brilliant.
Two general rules that hold across the whole shop. If the price is far below everything else on the shelf of that size, something has been substituted or treated. And a stone sold with no locality at all is usually one the seller cannot trace, which in this trade often means tumbled, dyed and bagged somewhere a long way from where it came out of the ground.
Aquamarine is usually linked to Pisces and Aquarius, and to Neptune. Worth being straight about this: crystal and zodiac pairings are modern, they are not consistent between sources, and two reputable books will give you two different signs for the same stone. They are a useful organising idea rather than a tradition with a single lineage behind it.
If you want the part of this that does have a fixed method behind it, the Sun in Pisces sets out what that sign actually describes, and it is calculated from a date rather than assigned by a writer.
Every piece of aquamarine in the shop is the same stone with the same associations, which is both the appeal and the limit of it. A birth chart is the opposite: it is calculated from your date, time and place and it describes one person. If you do not know your birth time, this covers how to find it.
Yes. At Mohs 7.5 to 8 it is hard and chemically stable, so water does no harm.
Yes, and permanently. Keep it off sunny windowsills. The colour will not come back.
Courage to speak, calm, clarity. It is associated with the Throat chakra.
Mohs 7.5 to 8. That is hard enough for daily handling.
Almost all commercial aquamarine is heat-treated to remove the yellow and leave pure blue, which is standard, stable and accepted in the trade.
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