Spring 2012 Color Inspiration

Hello Gemstone Lovers:

As I mentioned in my post about autumn colors, Pantone is a pretty good place to get some insight into new colors and trends.  So it was back to Pantone to check out their picks for Spring 2012.  Need a way to boost your mood?  Get a new outlook?  Update and look forward?  Then try adding a few of these hues into your accessories to up-date and change-up.  Naturally, I love the fact that one of the colors mentions a mineral by name, Sodalite Blue.  Might have to do a post on just that particular stone ...

I'm a little bummed that they didn't present the colors in that nice color-block format that they did for fall, since it was a nice, easy way to pick out some Lunar Blue items for our own color rainbow match.  So I made my own color blocks for matching! (This was harder than it looks.)

This palette has a lot in common with the autumn one, which is no surprise, since people don't want to have to buy all new clothes and completely repaint the interiors of their houses in order to feel "in sync" with the world.  The major difference seems to be that these are turned up a notch - a little brighter for the light colors, and a little darker for the contrasting colors.  It all seems to be more enriched compared to the cooler seasons behind us.  Again, not a surprise, since people want to add a little punch to their environment and dress this time of year. 

I particularly like the purples, pinks, and sage green colors in this group.  Certain hues of amethyst, rose quartz, peridot, and turquoise will match perfectly.  So will smoky quartz, picture jasper, yellow jade, and the deeper side of both lapis lazuli and sodalite.  A great selection of fun stones to work with!

Peridot - Part Four: The Universe Makes Stained Glass Windows

Some of the most beautiful meteorites in the world (and out of the world) belong to the pallasite class of meteorites.  Many pallasites can be recognized immediately by their characteristic crystals of greenish olivine embedded in an iron/nickel matrix.  When these meteorites are cut into thin slices, light can shine through the translucent olivine, creating stunning lattices of metal and gemstone.

The example at left is the meteorite Esquel.  Gorgeous gem quality olvine, known as peridot of course, is liberally strewn through a shiny metal frame.  It seems so perfect, one might think it was manufactured.  But these incredible rocks formed naturally, far away from Earth.

The meteorite Imalac is also a pallasite, with a higher density of olivine to metal, although the olivine is of a more golden hue, and seems less gem-quality.  Some pallasites are almost all metal, while others are predominently olivine.  Each is unique, its own version of a glittering mineral 'window.'  It once was thought that pallasites must come from the interior of an asteroid-like body - the place where the olivine mantle met the iron/nickel core.  But recent studies have indicated that things are not so straightforward.  Pallasites are a glorious mystery.

This gemstone gives us an immediate connection to the heavens.  Something as simply beautiful as peridot is found in abundance in the mantle of the Earth, and is one of the most basic minerals in space rocks, too.  Of course, the Earth is really just a big space rock, itself.

Image Credits: Slice of Esquel meteorite, from flikr via Creative Commons, CC 2.0, Bistrosavage. Closeup of Imilac meteorite, original image from flikr via Creative Commons, CC 2.0, aakova.

Peridot - Part 3: Weathering With Time

Hello Gemstone Fans:

I started this series of posts by saying that olivine was hardly a rare stone, what with it making up a substantial portion of the Earth's interior. And then, of course, I turned that on its head by saying that while olivine under the surface is common, olivine on the surface is hard to find. It is especially hard to find in the quality peridot needed to make cut gemstones, in fact.

The first reason such material is rare is that in order to get it to the surface, you need volcanism with magmas of the right composition, as I mentioned in my second post. The second reason is that olivine is not a particularly hard stone, and what peridot makes it to the surface weathers quickly. Weathering can take the form of physical weathering, which grinds down stones over time into small particles, and it can take the form of chemical weathering, where say water interacts with the stones and breaks down their crystalline structure.

On the Mohs hardness scale, peridot measures 6.5 to 7 (Diamond is the hardest at 10, with emeralds and sapphires at 9. Soft materials have low numbers, like talc at 1 and amber at 2.)  This means there are many harder materials in the environment that can scratch peridot, assisting in its break down.

But this phenomenon does have some interesting effects. There are places on Earth where you can find stretches of sparkling green sand. Hawaii is one of these places, where there are small beaches of sand largely composed of grains of olivine.

How do such concentrations of olivine grains come to be? Hawaii is, of course, a volcanic island, with active volcanism today. There are places on the island where the black rocks are rich in olivine crystals. As those rocks weather and break down, the crystals of olivine trapped inside are liberated, and moved by wind and rain downslope. A green sand beach may form in any area where the nearby rocks are rich in olivine, and where the shape of the coastline can protect the sand.  That way it collects there at approximately the same rate it is broken down or washed away. 

I have traveled to the most well known of these beaches (shown in the top image) the green sand beach near South Point in Hawaii. There are other beaches with sands of interesting color, such as black, pink, white, and red. But on this beach I got to walk barefoot on piles of tiny, glittering green gemstones. I felt a little like a dragon with a hoard of gems ...

Jennifer

Image Credist: 
Green Sand Beach, South Point Hawaii, Wikimedia Commons, CC 2.0
Green Sand Closeup from Mahuna Beach, Wikimedia Commons, Public Domain

Peridot - Part 2: From the Depths to the Surface

Greetings Gemstone Fans:

I mentioned in my post Peridot - Part 1 that the mineral olivine, known in gem-quality as peridot, can be brought up from depth by volcanism.  I visited one of these sites in New Mexico - Kilbourne Hole, a volcanic explosion crater - and got to see the results for myself.

Such craters are called "maar" craters, and are made by a shallow underground volcanic explosion. They were once confused with impact craters, which are caused by chunks of rock or metal from space striking the planet's surface. In fact, the craters on the Moon were thought by many to have been caused by volcanism, and were only shown to certainly be of impact origin after we visited there in person.

Kilbourne Hole is off the beaten path in southern New Mexico, but not so remote that it can't be found by dedicated stone hunters. (As it happens, I do not visit sites to hunt rocks, I visit them as a geoscientist, and was there to learn about the geology.) This maar is found on federal BLM land, not a national or state park, so is not protected in the same way. Larger crystals of olivine have long since been carried off by rock hounds, but there are patches of sand-sized green crystals remaining. Many of these were produced by rock hunters shattering thousands of olivine xenoliths looking for gem quality stones. There are only a handful of places on the Earth where olivine crystals are found on the surface like this, and so such sites are very popular.

Rarely at this site, one might find a volcanic rock, dark basalt, with splashes or crystals of bright green glassy material still clinging to it. The picture here shows just such a rock, encrusted with forsterite crystals. Forsterite is the name for olivine crystals that have a lot of magnesium in them, as opposed to fayalite, which is the more iron-rich end of the olivine spectrum. Such chemical differences are important to geologists who are trying to understand the volcanic history of the area.

It really is an amazing thought to look at this material and ponder how deeply in the planet it may have started its journey before making it to the surface. Not to mention the dramatic way it finally arrived.

Jennifer

Image Credits:

Kilbourne Hole - Bureau of Land Management, www.blm.com

Forsterite Crystals from Kilbourne Hole - Wikimedia Commons, Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Peridot - Part 1: Gem of the Earth's Interior

Greetings Gemstone Fans:

I thought I'd open up my blogging about beading materials with a series of posts on the gemstone peridot. This is the lovely green stone commonly known as August's birthstone. In gem-quality, it is peridot, but the mineral is known to geologists as olivine. The basic part of its structure is created by silicon and oxygen, as with most other 'rocky' minerals on Earth. Olivine also contains varying amounts of magnesium and iron.

We imagine that a gemstone held as precious by humans must be quite an oddity - something very rare. Yet olivine in its many forms is one of the most abundant minerals making up the planet Earth.

In fact, olivine accounts for the bulk of the Earth's upper mantle. The mantle is that thick, voluminous layer that sits between the Earth's thin crust and its core of iron and nickel. In this image, the mantle is (appropriately) green, with the upper mantle labeled as region three.

Because of the important role olivine plays in the Earth's composition, and its place in the upper mantle, geologists spend a great deal of time trying to understand how the mineral behaves at different pressures and temperatures, and which forms are created when and where. This information is needed to properly model heat flow, as well as the movement of the continental plates. So this stone is not only of interest to gem fans, it is a critical piece of Earth's geologic puzzle.

When you touch peridot, it is like touching the inside of the planet. Or possibly literally touching it, since some peridot is brought up to the surface from the depths by volcanism.

Jennifer







Image Credits:
Large Peridot Gem - From Picasa Web Albums, AfricaGems, via Creative Commons
Earth's Interior Layers - Wikimedia, via Creative Commons
Green Quartz and Peridot Necklace - Lunar Blue Designs, Amy's Personal Collection