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Heya !
I did a research on this forum and can't find the word "ulexite" so i put here my experiment of this day :
From wikipedia :
"Ulexite (NaCaB5O9·8H2O) (hydrated sodium calcium borate hydroxide) is a mineral occurring in silky white rounded crystalline masses or in parallel fibers
Ulexite is found with the mineral borax and is directly deposited in arid regions from the evaporation of water in intermittent lakes called playas. The playas form only during rainy seasons due to runoff from nearby mountains. The runoff is rich in the element boron and is highly concentrated by evaporation in the arid climate. Eventually the concentration is so great that crystals of ulexite, borax and other boron minerals form and accumulate to great thickness.
If the specimen is approximately an inch thick and is polished flat on both sides perpendicular to the fibers, then an unusual optical phenomenon can be seen. The fibers will behave like optical fibers and transmit an image from one side of the specimen to the other. In other words, a good specimen, resting on a newspaper will have the writing appear to be on top of the specimen without any distortion of the lettering. The newspaper can easily be read upon the surface of the ulexite! """
"What accounts for this unusual effect? The answer is that ulexite is a natural fiber optic material. Its parallel fibers exhibit total internal reflection, guiding light along the length of the fibers. As Jeff Hecht explains in his book City of Light: The Story of Fiber Optics (Oxford University Press, 1999), "Although ulexite was discovered around 1850, nobody took a close look at its optical properties until roughly a century later. It inspired no fiber-optic pioneers; some had never heard of it until I mentioned it. Only in 1963, several years after the faceplate was invented, did Bob Potter recognize ulexite as a natural fiber bundle.""
If you hold a polished slice right up to your eye, and look at a point source of light, you see concentric circles of light. This effect can also be produced by shining a laser pointer at a slightly oblique angle through a piece of ulexite. They explained this behavior as a consequence of different refractive indices in different directions of polarization.
here's mine (but not real ulexite, just gypsum which has the same optical property):
This picture show the letter HI trough a simple glass cube, and then with a piece of ulexite
And when i shine my triple :
edit : a rare picture of surface structure of ulexite with a Scanning Electron Microscope. We can see the fiber bundle (which are not round!). im collecting information to explain the interference pattern, and will do my own SEM picture in my physic department
I did a research on this forum and can't find the word "ulexite" so i put here my experiment of this day :
From wikipedia :
"Ulexite (NaCaB5O9·8H2O) (hydrated sodium calcium borate hydroxide) is a mineral occurring in silky white rounded crystalline masses or in parallel fibers
Ulexite is found with the mineral borax and is directly deposited in arid regions from the evaporation of water in intermittent lakes called playas. The playas form only during rainy seasons due to runoff from nearby mountains. The runoff is rich in the element boron and is highly concentrated by evaporation in the arid climate. Eventually the concentration is so great that crystals of ulexite, borax and other boron minerals form and accumulate to great thickness.
If the specimen is approximately an inch thick and is polished flat on both sides perpendicular to the fibers, then an unusual optical phenomenon can be seen. The fibers will behave like optical fibers and transmit an image from one side of the specimen to the other. In other words, a good specimen, resting on a newspaper will have the writing appear to be on top of the specimen without any distortion of the lettering. The newspaper can easily be read upon the surface of the ulexite! """
"What accounts for this unusual effect? The answer is that ulexite is a natural fiber optic material. Its parallel fibers exhibit total internal reflection, guiding light along the length of the fibers. As Jeff Hecht explains in his book City of Light: The Story of Fiber Optics (Oxford University Press, 1999), "Although ulexite was discovered around 1850, nobody took a close look at its optical properties until roughly a century later. It inspired no fiber-optic pioneers; some had never heard of it until I mentioned it. Only in 1963, several years after the faceplate was invented, did Bob Potter recognize ulexite as a natural fiber bundle.""
If you hold a polished slice right up to your eye, and look at a point source of light, you see concentric circles of light. This effect can also be produced by shining a laser pointer at a slightly oblique angle through a piece of ulexite. They explained this behavior as a consequence of different refractive indices in different directions of polarization.
here's mine (but not real ulexite, just gypsum which has the same optical property):
This picture show the letter HI trough a simple glass cube, and then with a piece of ulexite
And when i shine my triple :
edit : a rare picture of surface structure of ulexite with a Scanning Electron Microscope. We can see the fiber bundle (which are not round!). im collecting information to explain the interference pattern, and will do my own SEM picture in my physic department
