Ulexite is a natural mineral with weird optical properties due to the fibre optic like structure.
“Continue reading” for more details and photos.
There are unusual rings that form when a laser is shone through it as in the photo above.
The other property is the transmission of an image to the other side of a slice of polished Ulexite. This gives rise to the name “TV stone”.
Note how the image is displaced in this angled photo.
The image does appear to be on the surface of the specimen to the naked eye. It focuses there as well to the camera.
Ulexite with focus on top of specimen (rear becomes blurred)
The focus is on background of specimen (front becomes blurred)
Ulexite compared with a calcite crystal and an acrylic block. Acrylic has a refractive index of 1.49, whereas calcite is similar with ordinary and extraordinary refractive indices of 1.658 and 1.486. The acrylic is only half as thick so the image of the black line is only half displaced.
A dual power point outlet shows the unusual nature of the image. Clarity is lost at high angles but the image displacement is greater.
This shows the rings with a green laser. Vague rings are seen if you look directly at a bright light source through it.
Ulexite is hydrated sodium calcium borate hydroxide. It is found where Boron is prevalent in places such as California at the Boron mine.
This specimen is from Educational Innovations for the grand price of $9.95.
Related pages
Try something else
LiftersExternal links
Photo Date: 31/12/13