About Ethiopian Welo Opal

---

Opal had previously been discovered in the Shewa province of Ethiopia prior to 2008, and although that material is beautiful, it is very unstable and the vast majority of it develops cracks and can literally break apart.  Great for specimens, bad for jewelry!  This early material gave “African opal” a bad name.  The 2008 discovery of a new deposit, in the Welo province in the northern part of the country, quickly brought out the naysayers (most of them Australian opal dealers!) who claimed that this new material, too, was not stable.  The reality is that at the time, nobody really knew how stable – or not – this material actually was.  The story has a happy ending – 15 years into the discovery, this opal, once cut and polished, has turned out to be more stable, as well as more durable, than most Australian opal.

Hydrophane Opal

The Ethiopian Welo opal has some very unusual characteristics.  Most notable is its hydrophane property, which means it has an ultra low water content and can actually act like a sponge and absorb water – as much as 10% of its weight.  Opal has varying degrees of water in it, and traditional belief is that the higher the natural water content, the less stable the opal.  When Ethiopian Welo opal is immersed in water, it will soak up the water. As it does so, the opal’s color will first become very vivid, but as the saturation process continues, the opal will become completely transparent and the color disappears.  It is bizzare to witness, and had me completely flipped out when I first began cutting this material back in 2009!  Alas, all is not lost – this process is reversible.   As the opal begins to dry, it will first become very milky and opaque, and over the coming days – and in some cases weeks – it will gradually return to its original body color, color play, and degree of translucency.  It is important for jewelry artists who use these opals to educate their customers – Ethiopian opal is a dynamic stone and care should be taken to avoid prolonged contact with water or other liquids, oils, soaps, or even perspiration!

 A word to the Wise:  BEWARE of unscrupulous dealers who sell treated or dyed stones!!  Since this opal is so porous, it can be smoke- treated to significantly darken its base color to make it appear "black", or dyed to alter the base color.  Treated stones should ALWAYS be represented as such, and will always command a lower price than an untreated stone!  Every stone I cut and sell is 100% natural, free of any such treatments. 

Patterns, Colors, & Body Color

• Most Ethiopian opal is "crystal" opal, which refers to its translucent to transparent body color rather than physical composition.  Thinner stones will show their color best against a dark background.  This bares careful consideration when setting these opals.
• Many Ethiopian opals have beautiful color and patterns through-and-through the stone and may be polished on both sides or into free-form shapes.  This presents an interesting opportunity for the purchaser - one can choose which side they prefer for the "top" or in some cases the stone can be set to display both sides - but can be more challenging for the jewelry artist  to set.
• The "honeycomb" pattern is highly desirable, and is unique to Ethiopian opal.  This opal forms in a columnar manner which produces a striped pattern if cut on the side, and the honeycomb pattern when cut across the "top".
• Ethiopian opal is the only opal that displays a "rainbow" flash in which each patch of color is actually a full spectrum of color.  This is rare, as most opal consists of patches of individual colors.
• Reds and pinks are far more common in Ethiopian opal than Australian opal.
• Occasionally, a perfect, uniform crystalline formation occurs, and results in color patches that move evenly and continuously around the stone as it is moved.
• A flat surface results in a broader flash of color, whereas a more curved surface (or "higher" dome) results in smaller patches of color which roll over the stone as it is moved.  Which is "better" is a matter of personal preference!
• The base color - the color of the actual host opal itself - ranges from water clear to amber, brown, tan, white, and black. No other type of opal  displays such a variety of base colors. 

-