"Science is but a perversion of itself unless it has as its ultimate goal the betterment of humanity."   Nikola Tesla
“If you want to understand the secrets of nature, look to vibration and frequency...”  said Nicola Tesla - Great Humanitarian and brilliant scientist, it seams he was the only one, who understood the Universe as a vibration, frequency and knew how to utilize it, and benefit from it.

"All matter comes from a primary substance, the luminiferous ether," stated Nikola Tesla. He sensed the universe was "composed of a symphony of alternating currents with the harmonies played on a vast range of octaves," wrote Margaret Cheney. "To explore the whole range of electrical vibration, he sensed, would bring him closer to an understanding of the cosmic symphony." Nicola Tesla - "Man out of time"

Nicola Tesla (1856 - 1943) scientist, electrical engineer, he was a pioneer in many fields of electrical theory and technology, a discoverer - as he called himself - with superb imagination, he knew how to manifest his dreams into reality, how to serve HUMANITY...
Some of his discoveries: Tesla coil transformer, radio, fluorescent lights, telephone repeater, wireless communication, alternating-current power transmission, principle of rotating magnetic field, polyphase alternating-current system, induction motor,  and more than 700 other patents. 

Purple Plate was one of his ideas as well.

Linda Goodman, the famous writer and astronomer, gave Tesla Plates the name "the purple plates" and because of her book "Star Signs" the purple plates are popular all over the world. 
She wrote that the person who was working with Nkola Tesla on creation of the plates preferred to remain anonymous. However, after his death the company which produced the plates decided to give him due credit. The man who was working with Tesla was Ralph Bergstresser, (1912-1998). He is also know by his "Dr. Nikola Tesla: Forgotten Superman of Our Industrial Age".

Each Plates produced by his company has very well visible seal, his company's logo, they are authentic - original. 

Purple - the color of St. Germain

     
An altered anodized (electrolytic oxidation) aluminum plate in purple color acts as a transceiver (transmitter and receiver) of LIFE ENERGY/FORCE - free vital energy, to alter anything and everything in its proximity, for the benefit of plant, animal, human, food, and soil. To increase the vital energy, to neutralize the harmful one.. Many people use them to support physical healing (migraine headaches, wounds, etc.) or they carry them around in order to raise their vibratory frequency. Chemical composition and vibration of the plate is almost the same as rubies and sapphires, which also consist of aluminum oxide and they have been called for ages “the life stones”. Practically, it lasts for years, unless  dematerializes itself (some say it sometimes happens), no one knows how or why. May be - there is some type of energy, we are not able to comprehend, and that is what some call  MAGIC...

NOTE: There is plenty of info on the world web pages.