This is a superb twinned selenite. The twinning is quite evenly developed, so that this piece is almost symmetrically twinned. The crystals are sharp, with good transparency, and small horizontal indents/inclusions – the indentations are all fully crystallized surfaces. In excellent condition – no damage as displayed, a chipped area at the back of the narrow end of the specimen. Great twinning!
The third photograph is in short-wave ultraviolet light, showing the internal pattern.
About these Selenites
These selenite specimens were recovered during a project at Willow Creek, near Nanton, Alberta in the early 1990s. The occurrence was in clay, which preserved and protected the crystals from weathering.
Willow Creek selenite crystals are fluorescent under ultraviolet light, exhibiting an “hourglass” pattern that is not visible in normal light – this can be seen in the one photograph. It is clearly visible in short-wave, medium-wave and long-wave ultraviolet, most prominent in short-wave. These crystals are also phosphorescent – the hourglass pattern remains briefly visible in a green hue in total darkness after the ultraviolet light source is extinguished – the selenite crystal then fades and then it too is dark.
These selenites are in excellent condition.
Willow Creek selenites are some of the finest known from Canada. They are super crystals!
[Notes about care: Selenite has a low surface hardness, and care should be taken to protect from scratching. Selenite is also sensitive to repeated or prolonged exposure to water (it will lose lustre), so this should be avoided.]