The four main devices (symbols) in the Mountjoy blazon are the barry nebulee, castle, escutcheon and barry wavy. The three main tinctures (colors) are argent, or and sable .
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) 1Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 2A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
Or is the heraldic metal Gold, often shown as a bold, bright yellow colour. It is said to show “Generosity and elevation of the mind” 3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35. Later heralds, of a more poetic nature liked to refer to it as Topaz, after the gemstone, and, for obvious reasons associated it with the Sun 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In drawings without colour it is usually represented by many small dots, or by the letter ‘O’ 5A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P76-77.
Sable, the deep black so often found in Heraldry is believed to named from an animal of the marten family know in the middle ages as a Sabellinœ and noted for its very black fur 6A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Sable. In engravings, when colors cannot be shown it is represented as closely spaced horizontal and vertical lines, and appropriately is thus the darkest form of hatching, as this method is known 7Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 26. Although it may seem a sombre tone, and does indeed sometimes denote grief, it is more commonly said to represent Constancy 8The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35.
When the field of the shield is filled with alternately coloured horizontal lines, this is known as barry, obviously because it is like having many separate bars across the field 9A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Barry. As well as being drawn with straight edges, there some decorative effects that can be used, and, with careful, these can be very pleasing. The decorations are typically much smaller than those used on the major ordinaries, such as the fess so care must be taken to ensure clarity. Nebulee (sometimes nebuly is a very pleasing pattern of interlocking curves, the name refers to “clouds” as it is reminscent of their soft abstract edges.
Architectural items, from individual components to entire buildings 10Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 92 feature frequently as charges In a coat of arms. Not surprisingly, considering the times from which many arms date, fortifications are common. The castle is perhaps second only to the tower in this usage, and often described in some detail as to its construction, the disposition of windows and so on. 11A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Castle Continental examples also sometimes include attackers on scaling ladders. Wade tells us that the appearance of a castle indicates “granduer and solidity” and one can understand why. 12The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P100
The escutcheon simply represents smaller shield shapes included within the shield, and its close relative, the inescutcheon is just a larger version occupying most of the field. 13A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Escutcheon There is no particular significance that can accorded to the escutcheon itself, but attention should be paid to the colour and devices that are borne upon it. The escutcheon may also be added to an existing coat of arms either as recognition of some additional honour (an escutcheon of augmentation”) or in the case where arms that are already quartered are to be combined an escutcheon with the new arms may be placed overall (an ”escutcheon of pretence”). 14Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 126 & 141