Cordierite lesser used among jewelry designers is a semi precious stone with some of the strongest changes in colour across viewing angle known, radiating large shifts in colour from rich sapphire blue to near crystal clear.

Culturally important to the Nordic peoples of ancient Europe who used thin sheets of crystal as a polarising filter to help them navigate from the sun, synthetic cordierite helps to clean the modern world every minute of every day – being used in nearly every catalytic converter on Earth.

With our fashion design cordierite with strong blue colouring projects a confident palette for lovers of ocean blue tones, contrasting beautifully to clothing with mesmerising eye catching flashes of lightness.

Formation of a Cordierite Gemstone

Cordierite is part of a special family of silicate minerals known as a cyclosilicate, in common with tourmaline and beryl these silicon rich minerals have their primary elements joined together in a ring.

Silicates are some of the most important contributors to the geologic cycle of our world, involved in processes where they are weathered, crystallised, melted and metamorphose into countless varieties of minerals such as quartz gemstones.

Cordierite begins it’s journey countless aeons ago as silica rich clays that are pressed down into the earth in endless plate tectonic upheavals.

Bearing great pressure under the Earth’s surface, these silica rich clays are compressed into sedimentary rocks called pelite.

Pressed ever downward these rocks are continually heated proximately or through direct contact with extrusions of deep hot igneous rocks and further change in composition, forming minerals that include garnet, spinel, kyanite and cordierite.

Shifted onward and upward these changed rocks can resurface or are exposed by weathering of surrounding rock, sometimes found on the surface in concentrations of tough durable “hornfel” outcroppings of colourful banded rock.

Appearance of Cordierite

Known as “iolite” when described as a faceted gemstone, cordierite has been called the “water sapphire” where discovered in Sri Lanka due to it’s simultaneous display of ocean blue tone when viewed from one direction, to water clear transparency when viewed from another.

“Pleochroism” is the display of different colours when viewed from differing viewing angles, and cordierite exhibits some of the strongest pleochroism known among gemstones.

In early European history cordierite was named “dichroite” after the Latin for “two colours”, these special crystals that exhibit pleochroism bend light differently depending on the polarisation of the light that enters it.

Cordierite shows very strong pleochroism, from violet and darker blue tones to yellow and transparent tones can be viewed from different directions and are a useful way to determine if a gemstone is genuine cordierite.

Though frequently cut into faceted gemstones, cordierite’s special affinity to changing colour requires careful selection of the principal face of the gemstone to ensure the strongest desired colour projects along that axes.

The most sought after colours of cordierite are the violet-blue types in larger carat faceted gemstones, these predominately blue colour tones as with amethyst and many other gemstones comes from the presence of iron elements scattered throughout the crystal.

Included cordierite gemstones are not sought after in faceted gemstones though the tracery of natural fracture lines and traces of other elements are often present in beads and cabochon jewels.

In some cases these included elements locked within the crystal can form long rutile threads that produce “cat’s eye” chatoyancy in similar vein to the gloss of light reflected from a spool of fine threaded silk.

Cordierite Gemstone Culture

Historically cordierite is best known for it’s use by ancient Viking seafarers who pioneered the use of using the sun and the stars to navigate away from the coast on steady bearing towards unknown shores then back home again.

Owing to the often clouded skies of Northern Europe these ancient mariners with their dependence on the sun for daylight navigation found that thin sheets of these blue mineral would show the sun even through heavy cloud, allowing them to successfully hold a fixed course in unforgiving weather.

The same crystal properties that change the colour of cordierite from ocean blue to crystal clear scattered the randomly polarised light of the sun as it passed through heavy cloud, preserving more of the original light and consequently changing colour when proximately directed at the true location of the sun.

In the modern age cordierite was named as distinct mineral gemstone by the French geologist Louis Cordier in Spain 1831 and was found to have additional remarkable properties that are now utilised to this day.

Though of a hardness on the same par as natural quartzes, cordierite was found to be exceptionally stable when exposed to large changes in heat.

Reproduced into synthetic gemstones, countless small crystals of cordierite act as a super hot medium aiding the catalysts work of making exhaust emissions less harmful.

Cordierite Gemstone Fashion

Deep ocean blue is one of the first impressions that comes from the natural palette of cordierite, balanced with clearer tones that change with the angle of view and lighten the overall feeling like the crests of waves on the sea.

To lovers of blue tones cordierite is a devoted companion, naturally matching well to light blue apparel where it adds depth to a look, and darker blue tones layering further attention in detail.

Our designer necklaces and bracelets crafted from cordierite gemstone belong to our ocean concept designs, featuring peaceful projection of stable emotion and rich blue colour that is very eye catching.

Larger carat size cordierite beads show deep blue colouring with shifts of colour tone with viewing angle that enhance the overall lightness of the piece when worn, a befitting addition to our range of vibrant colour necklaces and bracelets.

Cordierite is a colourful crystal that guided ancient mariners across new seas and today guides us towards a cleaner world, with ocean blue colouring and life full shifts in tone this gemstone adds life and energy in a new way to jewelry and dress.