The Rose Cross Lamen was the most important teaching symbol of the outer order of the Hermetic Order of the Golden Dawn, an eighteenth century magical society. It has been said to contain all of the knowledge of the order in its complex symbolism. Based on the Rosicrucian Rose cross, it is a kabbalistic glyph-essentially, a tree of life- containing a number of formulas, among them all of the “King scale” colors assigned by the GD to the Tree of Life, the four alchemical elements, and the planets of the zodiac. 
 
In the center of the cross is a rose with twenty-two petals symbolizing the letters of the Hebrew alphabet and colored accordingly, which is often used as a device for creating sigils. The four emanating rays illustrate the tetragrammaton and the formula of INRI (Yod-Nun-Resh- Yod) and the tetragrammaton.
 
Additionally, the RC lamen served as a symbol of office of Chief Adept. When Aleister Crowley was ejected from the order, he adopted the symbol as an emblem of his OTO (Ordo Templi Orientis). 

The symbolism remained much the same, although he attributed to it many elements of his philosophy of Thelema and revelations about the the goddess/god pair Nuit and Hadit.

In the nineteen-fifties, the cross was modified from its original form and adapted for use as an emblem of Scientology by Crowley admirer L Ron Hubbard. 

Golden Dawn Rose Cross Lamen