Sister Stones - Ethical Sapphires and Rubies

There’s this wonderful expression in Indonesian… ‘serupa tapi tak sama’, which means ‘similar but not the same’ (or ‘same same but different’, as the tourist t-shirts would say). 


This perfectly captures the relationship between sapphires and rubies. 


These gemstones are like siblings who love to geek out over shared hobbies, and spend entirely too much time sending each other memes to laugh over.


Sapphires and rubies are the two gem varieties of Corundum, and they’re tough as nails! In its pure form, Corundum rates a 9.0 on the Mohs scale. 


Their hardness is one of the reasons why sapphires and rubies are such a popular choice for wedding and engagement rings. 


Let’s be honest, the color alone is enough for anyone to fan themselves and go ‘oh la la, hello gorgeous’.


Science is so cool.

Borneo Sapphires and Rubies with Hidden Gems Rings in Eco Gold

Check out these sister stones, standing side by side. Ravishing rubies and stunning sapphires on our Hidden Gems Ring in Eco Gold with ethical gold mined by our indigenous women miners.

How are sapphires and rubies differentiated then? It’s all about how gemstones get their color. Most gemstones get their color from ‘impurities’ or trace elements in their crystal structure. 


For example, pure Corundum is colorless, while sapphires and rubies are differentiated based on a slightly different chemical compositions. 

The chemical make up of sapphires

It’s a small trace of another chemical coming into contact with the stone during its formation that makes all the difference - that creates that gorgeous array of colors.

The blue sapphires that first come to mind when thinking of sapphires, are made with the addition of titanium. 


But blue isn’t the only color for sapphires. There’s pale yellows and greens (trace amounts of iron), purple (trace amounts of chromium, iron, and titanium), pink (trace amounts of chromium), some look grey in certain lights, and sometimes they can even be close to colorless.

The ‘impurity’ that gives ruby its lovely shade of love is chromium.  Notice how ‘impurity’ is in quotation marks? Even though it's used scientifically to describe the process of how Corundum changes color.  

I’m more inclined to call it ‘the secret ingredient’.


Chemistry was never my strongest subject in school. So abstract, even though my high school teacher made a good effort singing songs about atoms. But encountering chemistry in adulthood in relation to gemstones? Science is the coolest. Nature is amazing. And I Iove shiny things. 

Chromium turns corundums into rubies!
Sapphire rings from the Borneo Gems collection

We’ve discovered gorgeous shades of sapphires in Borneo, and in our journey – we’ve also discovered rubies. 


Right now, we have a very limited stock of rough, uncut sapphires and rubies from Central Kalimantan in our safe. A dazzling array of pastel-colored sapphires in soft, seafoam shades and forest hues from one village. More saturated and deeper colors from an upstream deposit. And a very, very limited stock of vibrant ruby shades.


Have a look, and tell me your favorite shade of corundum! And let me know how you like your stones; do you prefer cut and faceted, or do you go for rough beauties?




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