Where is olivine found in the world?

Olivine: Earth’s Deep Green Secret (and a Space Traveler!)

Olivine. Ever heard of it? It’s not exactly a household name, but trust me, this mineral is a big deal. Chemically speaking, it’s a magnesium iron silicate – (Mg,Fe)₂SiO₄ if you want to get technical. But what really makes it fascinating is where it’s found: deep inside our planet, and even floating around in space! That cool olive-green color? That’s where it gets its name. And when it’s gem-quality, we call it peridot – a gemstone with a history as rich as its color.

Most people think of minerals as just, well, earthy things. But olivine’s story goes way beyond our backyard.

From Earth’s Core to Your Backyard (Maybe)

Olivine is a major player in the Earth’s upper mantle. We’re talking about roughly 60% of the rock down there! Think of rocks like peridotite – those are basically olivine central. And if you ever stumble across mantle xenoliths (chunks of mantle rock brought to the surface by volcanoes – how cool is that?), you’re almost guaranteed to find olivine.

Now, this mineral loves hanging out in mafic and ultramafic igneous rocks. Basically, when magma that’s loaded with magnesium and low on silica cools down, olivine crystals start forming. This leads to rocks like gabbro and basalt. But the real olivine superstars are ultramafic rocks like dunite and peridotite. Dunite can be over 90% olivine! The way these rocks form is pretty neat too – the olivine crystals are heavy, so they sink to the bottom of magma chambers, creating these super-concentrated deposits.

Not Just Underground: Where Else Can You Spot It?

Okay, so olivine is a big shot deep down. But what about on the surface? Here’s the thing: olivine isn’t exactly the toughest cookie when it comes to weathering. It breaks down relatively quickly. Still, you can find it in a few different spots if you know where to look.

• Igneous Rocks: Keep an eye out for those dark-colored igneous rocks. Basalt, gabbro, peridotite – they often have olivine crystals embedded inside. You’ll find these kinds of rocks near spots where tectonic plates are moving apart, and at volcanic hotspots.
• Metamorphic Rocks: Olivine can also show up in metamorphic rocks, especially serpentinite. This happens when olivine-rich rocks get transformed by water and pressure. Also, in areas where hot magma meets dolomites, you can sometimes find cool olivine cousins like forsterite and monticellite.

Olivine’s World Tour: From Norway to Mars!

So, where exactly do you find olivine around the globe? Well, it’s pretty widespread, but some places are olivine hotspots:

• Norway: This country is basically the king of olivine. Seriously, they’re estimated to have about half the world’s supply, especially in the Sunnmøre district. The biggest commercial deposit? You’ll find it near Åheim.
• Europe’s Got It Too: Lots of other European countries mine olivine, including Sweden, Finland, Spain, Italy, Austria, Greece, Cyprus, and Turkey.
• Oman’s Hidden Treasure: The Sultanate of Oman has tons of olivine, like 14,700 cubic kilometers worth!
• Global Players: China, South Africa, Mexico, Australia, and the United States are also in the olivine game.
• Down Under Surprise: New South Wales in Australia has some promising olivine deposits, with the Doonba dunite deposit being the most interesting.

Olivine Goes Interstellar

Now, for the really mind-blowing part: olivine isn’t just an Earth thing. It’s been found in meteorites and on other planets! Talk about a traveler.

• Meteorites: You can find olivine, especially the iron-rich kind called fayalite, in iron-nickel meteorites. And in those stony meteorites called chondrites? Olivine is often hiding inside these little spherical blobs called chondrules.
• The Moon’s Green Spots: The Japanese lunar mission SELENE/Kaguya found a bunch of new olivine-rich areas on the Moon, mostly around big impact craters.
• Mars’ Olive Hue: Even the Red Planet has olivine! Scientists have spotted it on the surface using data from the Mars Global Surveyor.

More Than Just a Pretty Rock: What’s Olivine Good For?

Okay, so olivine is cool to look at and has an amazing backstory. But what’s it actually used for? Turns out, quite a lot!

• Gemstone Glamour: When olivine is clear and beautiful, it becomes peridot, a gemstone that’s been prized for centuries.
• Tough Stuff: Olivine can withstand crazy high temperatures, so it’s used to line furnaces for making steel.
• Foundry Magic: Foundries use olivine sand for casting molds because it’s so stable when heated.
• Climate Hero? Here’s a cool one: olivine can actually capture carbon dioxide from the atmosphere through a natural weathering process!
• And More! Olivine is also used in steelworks, as an abrasive, to improve soil, and as a filler material.

So, there you have it. Olivine: a mineral that’s abundant, beautiful, and found in some of the most unexpected places. From the Earth’s mantle to meteorites, this deep green secret is a reminder that our planet is just one small part of a much larger, and much more fascinating, universe.