Circle
The circle is pre-Christian and its original symbolic meaning has been adopted by Christianity. It is universally known as the symbol of eternity and never-ending existence. Extremely common on gravesites, its usual representation is a cross surrounded by circle. Two circles, one above the other, represent earth and sky. Three interconnected circles represent the Holy Trinity.
Latin Cross surrounded by circle or oval representing eternity or never-ending existence.

Triangle/Trefoil/Triquetra
In Christianity, the equilateral triangle is the symbol of the Trinity. Other geometric shapes representing the Holy Trinity are the trefoil, the triquetra, the circle within the triangle, the triangle in circle and the triquetra and circle. To the ancient Egyptians, the triangle was an emblem of Godhead; to the Pythagoreans, it symbolized wisdom. Another use of the triangle is in the symbol of the eye (eye of God) surrounded by a triangle.

Square
It represents the earth and earthly existence. Some monuments have a cube or square inverted to point the corners downward and upward. This illustrates earthly existence and the directions of earth and heaven.

Pentagram
This is a five-pointed, star-shaped figure made by extending the sides of a regular pentagon until they meet. This figure pre-dates Christianity and was first known to be used by Pythagoras, the Greek philosopher. Later in the Middle Ages, the pentagram was used by magicians and sorcerers. It was believed that the pentagram offered protection against evil. Christianity adopted the figure and the symbolism to suggest the five wounds suffered by Christ on the cross. It is interesting to note that the pentagram is used by both Christianity and Wicca (witchcraft).

Star
A five-pointed star is symbolic of the life of Christ and may also represent the five wounds of Christ.

Five-pointed pentagram star
This star is drawn with one stroke of the pen. Its exact origin is unknown, and its meaning has changed throughout the ages. The pre-Christian Celtic priests called it the witch’s foot. It is also called Solomon’s Seal and was known in the Middle Ages as the goblin’s cross. Today the symbol is a favourite among graffiti artists and so-called demonology practitioners. Like the pentagon, it is believed to have protective powers against evil. In Wicca beliefs, it represents protection against demons and a symbol of safety. The ancient Babylonians used the symbol as a magic charm. The five-pointed pentagram star represents the five senses. To the Jews, it represents the five mosaic books. This symbol has also been adopted by Masonic organizations (e.g., the Eastern Star).

Six-pointed star or Star of David
Also known as Magen David (Hebrew for shield of David), it is typically used as a symbol of Judaism. The star is actually made of two triangles. It signifies divine protection as epitomized by the alchemistic signs for fire and water which are an upward and downward apexed triangle. The star is a very ancient symbol, used by several Asia Minor cultures, as well as some Greek city states. For Judaism, the Star of David came into widespread use at the beginning of the 20th century. Theodore Hertzel, a Jewish activist, adopted the symbol in his writings promoting Palestine as a Jewish homeland.

Menorah or seven-branched candlestick
Jewish symbol for divine presence of God. The seven branches of the candlestick represents the seven days for the creation of the world by God.

Swastika
Exact origin is unknown but it is considered one of the oldest and widespread symbols used. Commonly found on Buddhist memorials, it represents the seal of the Buddha’s heart; the doctrine of Buddha; the round of existence. To the Chinese, the swastika had two forms symbolizing the male and female; clockwise and anti-clockwise. Also used by the Romans and later by the Nazi party in Germany during the Second World War.