Rolex, Ref. 5100 - limited edition of 1,000 examples The Rolex Quartz, Ref. 5100, was launched on April 10, 1970 and was the very first quartz watch produced by Rolex. This watch was the result of Rolex's participation in the Centre Electronique Horloger, which was founded in 1962 by a group of approximately twenty Swiss watchmakers, including Rolex, Audemars Piguet, Omega, Piaget and Patek Philippe, to develop an electronic movement for use in wristwatches. The result of this collaboration was the Beta 21, a 13 jewel, 8Khz quartz module first seen in prototype form in 1967 after the unsuccessful Beta-1 and Beta-2 projects were abandoned. In 1968 an industrial consortium of Swiss watch manufacturers was created to mass-produce the Beta 21. This was truly a collaborative effort among what were otherwise competing watch companies, all of whom would be using the Beta 21 in their own brand of quartz watches. The CEH itself designed the module and produced the integrated circuit, Ebauches SA (now ETA) manufactured the mechanical parts of the movement as well as the quartz oscillator and Omega was responsible for producing the micro-motor that drove the hands. This "motor" was in fact a vibrating unit that drove a tiny horizontal pendulum set to oscillate at 256Hz and this pendulum drove the hands by means of a ratchet and index wheel. The end result was that unlike with modern quartz movements, the second hand of a Beta 21 watch moved around the dial smoothly, as opposed to one-second jumps as is commonly found in modern quartz watches. Final assembly of Beta 21 movements took place in three different manufacturing facilities, with very limited modifications to the movements being made depending on a brand's specifications. The ref. 5100 debut was greeted with initial orders far exceeding Rolex's expectation, with the planned production run of 1000 watches selling out before the first finished watches had been made. In the end, all 1000 individually numbered watches were sold between 1970 and 1972. From an aesthetic perspective the ref. 5100 was a styling triumph and a departure from the traditional Rolex style with a clean, modern design that utilized an integrated case and bracelet crafted entirely from 18K gold, approximately 800 in yellow gold and 200 in white gold, the crystal on the watch was synthetic sapphire, also a first for Rolex. Despite Rolex's own high praise for the 5100, this watch was an anomaly because they had to work with an existing movement, and only limited modifications could be made to it. Rolex to all intents and purposes had to design the watch around Beta 21 movement. This meant that the Oyster case, a cornerstone of the Rolex reputation, could not be used and as a result the 5100 was listed as "water resistant" and not "waterproof." In addition, the ref. 5100 contained a movement that was, with the exception of some small modifications, identical to that found in the watches of sixteen other companies. This put Rolex in a position they had not been in since the 1930s when J. A. Aegler produced movements for both Rolex and Gruen. Consequently, in 1972 they withdrew from the CEH as well as the Beta 21 project and began developing a quartz movement of their own design.