The most likely reason that there are two Quinn family crests is that there are two unrelated or distantly related Quinn families that received crests or created their own.
Certainly. Very few families actually have family crests.
Surnames don't have family crests; families have family crests. For any given surname there can be several unrelated families, each with a different crest, and many more unrelated families with no crest at all.
Italian noble families do have crests. They are often seen above the entrance to the palazzos the family owns or owned. However, just as in other countries, most Italian familes are not part of the nobility and do not have family crests.
Names do not have crests or coats of arms. Some individuals have coats of arms. Some families have crests; and some families of the same name do not.
There are a great many different Smith families. Most will not have a family crest since most blacksmiths, copper-smiths and the like were not in the social classes that had crests. Any two that do have family crests will have different crests.
You can find German family crests at familycrest.com, or at houseofnames.com
Most families do not have, and never had, colors or crests. These were symbols used by royalty, the nobility, and certain churchmen (who theoretically should not have had descendants). If your family has such symbols, they will be recorded by the officials responsible for Heraldry in the country where the colors or crests were first used.
The crest of the Montague family is a silver eagle on a field of blue, while the crest of the Capulet family is a red eagle on a field of gold. These crests are symbolic of the two rival families in William Shakespeare's play "Romeo and Juliet."
Crests and similar symbols were means of identifying important people at a time when most people could not read or write.
The two families fighting both had roses in their crests. One family's roses were red, and the other's were white.
they were the repositories or keepers of the family's history