From the Archive: (Inter)stellar Gemstones
Gemstones are beautiful. Everyone knows that! They are flowers of the mineral world, treasures from deep within the Earth.
Most of the time.
There are some gems that are a special breed of stellar minerals. Interstellar minerals that is!
That’s right, there are some amazing gemstones that come from the stars above, or have been found on other planets. These gems aren’t just rare, durable and beautiful; they are (literally) out of this world!
Opal is comprised of a silica gel substance, usually with a small percentage of water present. The silica forms microscopic spheres that stack upon each other to form opal.
Opal deposits are usually found in cracks and fissures; places where the silica was allowed to seep long ago. Usually, the “gel” is a byproduct of an acidic water-based compound. We know of our opals here on Earth, but what about on Mars?
In 2007, the Mars rover Spirit discovered many deposits of a silica-based rock that looked an awful lot like opals. NASA confirmed it was silica by using false color imaging and the spectrometer, which collects approximately 544 colors (wavelengths) of reflected light to detect minerals on the surface. The minerals are most prominent on outcroppings and in cliff basins in one section of the planet.
These were a surprising and important find on our neighboring red planet because it proves there was, at least at one time, water on the surface.
Perhaps someday they will be able to obtain a sample of this Martian Opal and take a closer look. Will it look like our opals or will it stun us with a different kind of beauty?
For now, they often call it Opaline Silica and eagerly study what they can of this Martian feature as it might hold clues to Mars many ages ago.
Peridot is the gem variety of the mineral olivine with the chemical formula (Mg, Fe)2SiO4 – magnesium, iron, silicon, and oxygen. It’s the birthstone of August and is famous for its almost shockingly energetic green color.
On Earth, this gem is found in igneous rocks. Not on Earth, you might see it on a meteorite! The gems have been on pallasite, and around, meteorite impact craters.
The interesting thing to note is that peridot can’t handle super high temperatures, so the outer “shell” of meteorite must have protected it and burned off instead, as it entered the atmosphere.
It is also been observed as interstellar dust. This “dust” is seen in the tails of comets, the disks around young stars, and at the sites of impact craters.
This evidence suggests that the mineral olivine quite possibly was present at the creation of many planets. Perhaps even our own.
Usually, the peridot found on meteorites is small and pale in color, due to the extreme conditions from once it came. GIA laboratories ran a series of tests on the “space” versions of peridot and found key differences in the chemical makeup of the stones, meaning they can always tell if it’s an Earth grown peridot or a visitor from the stars.
The gemstone is often called the stone of sun, maybe that’s a little more literal than we thought.
Quartz and Feldspar
Quartz and feldspar are two of the most common minerals found on Earth, and makeup not only gemstones such as amethyst, citrine, chalcedony, and moonstone (among others,) but also sand, marble, ceramics, and plastics.
Quartz and feldspar are massive groups of minerals, and since it’s abundant on Earth, we fully expect to see it elsewhere in the universe!
But what might we see if we find these rocks far, far away?
Will we find a bright blue quartz, naturally colored?
A giant moonstone spire that stands taller than a skyscraper?
An entire planet of nothing but crystal?
No one is sure but the possibilities are endless!
The presence of these minerals tells us that other worlds may not be as different as our own, despite appearance. They were all formed in the same universe, after all.
Many types of “diamonds,” or something kind of like them, have been found. Some of these minerals are made of carbon but form in a different crystal structure. Since the crystal structure is unique to diamonds and is partially responsible for how tough and durable diamonds are, these stones have a key difference.
Others are small pieces, considered dust. There’s even some that form flat-like sheets, instead of how they form here on Earth.
There’s a bit of a debate if any of these can truly be called “diamonds,” but either way, they are unlike the gems we have here on Earth.
Multiple forms of glass have been found at impact craters, but the interesting thing about them is that they are often colored. We tend to think of glass as clear, transparent, but the majority of “natural” glass formed by impacts is green! Some of this is called Moldavite.
Discoveries are happening daily about the world beyond our own, and who knows what’s next.
Perhaps someday in the near, or distant, future, we’ll be talking to clients about setting “space” stones into rings, and working on marketing some rare mineral from a million light years away.
With the variety of minerals on Earth alone, the sky’s not even the limit on what we could discover!
Here’s to the rare, durable and beautiful gemstones that make our planet special.
And, apparently, other planets, too.