The main device (symbol) in the Mniszech blazon is the feather. The two main tinctures (colors) are gules and argent.
Gules, the heraldic colour red is very popular, sometimes said to represent “Military Fortitude and Magnanimity”1The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P36. It is usually abbreviated as gu and in the days before colour printing was shown in a system known as hatching by vertical lines 2Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P52. Although it may look like a French word it is normally pronounced with a hard “g” and may be derived either from the Latin gula (throat) or Arabic gule (rose).3A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P154
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.
The feather, especially that of the ostrich appears with great regularity in the crests of a full achievement of arms, typically in the shape of a plume. Wade associates this device with “willing obedience and serenity of mind”. 6The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P74 They are much less common on the shield itself, unless part of an arrow, which may be feathered of a different colour, or a quill pen. 7A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Feathers