The main device (symbol) in the Cratford blazon is the unicorn. The two main tinctures (colors) are gules and argent.
Red in heraldry is given the name Gules, sometimes said to be the “martyr’s colour”1The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P36. The colour is also associated with Mars, the red planet, and the zodiacal sign Aries 2Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. Later heralds of a more poetical nature would sometimes refer to the colour as ruby, after the precious stone.3A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P77.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 5A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
In the mediaeval period there was no real percieved difference between real and mythical animals, after all, much of the world remained unknown and who was to say what strange and magical creatures existed in distant lands? As heraldry developed a whole menagerie of imagined creatures 6Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P164 came into being, and their various representations became more or less standardised in form and appearance. The unicorn is an intresting example that is still part of our own mythology today. The unicorn as illustrated on even the most ancient coat of arms is still instantly recognisable to us today, and shares many of the same poses that both lions and horses can be found in. 7A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Unicorn. Wade, the 18th century heraldic writer suggested that were adopted as symbols because of “its virtue, courage and strength”. 8The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P85