Crosses are usually a religious symbol and are plentiful in the cemetery. There are many types of crosses which may provide additional information about the beliefs of the deceased. The images below represent crosses that I have found in cemeteries in the United States and certainly is not a complete list of cross types. Seiyaku is a nice site for cross identification.
Ankh or Egyptian
Ancient Egyptian symbol of life; the universe; all life both human and divine.
Basque
The Lauburu or Basque cross was generally used as a symbol of prosperity in heraldry. May mark the tomb of healers of animals and healers of soul. The Lauburu (four heads), a traditional Basque emblem has four comma-shaped heads.
Botonee, Three-lobed, Budded or Trefoil
The Budded Cross. Three lobed ends or buds, representing the trinity. Also known as Trefoil, Bottony, Botonee.
Calvalry Cross
A Latin cross, usually mounted on three steps. The ascent represents the climb Christ made to Calvary. The three steps are a reminder of the three principles of faith, hope, and charity or the Father, Son, and Holy Ghost.
Celtic, Ionic
The Celtic or Irish Cross is a cross within a circle which stands for eternity. The Celtic Cross at the left includes the four evangelists with a phoenix in the center.
Many Celtic crosses include intricate knot patterns, also known as Celtic knots.
Chi Rho or Labarum
The letters X and P are the Greek letters for Chi Rho, an abbreviation for the word Christ. The Chi Rho Cross is a warrior’s cross.
Crown with Cross
The Cross with a Crown is a Christian symbol of sovereignty of the Lord. It is also an emblem used with the Christian Scientist religion and is a symbol of the Knights Templar.
Crucifix
Symbolizes the mode of the death of Jesus Christ, and faith and resurrection.
Fleur De Lis
The Fleure-de-lis cross is adorned with lily petals at the arm ends. Similar to the Fleurie cross.
Fleurie
The Fleurie (Flory, Floretty, Fleuronny) Cross has three lobed ends which represent the Trinity when used as a Christian Cross.
The three petals represent faith, wisdom and chivalry when used in heraldry, and the Trinity when used as a Christian Cross.
Greek
The Greek Cross has four equal arms and is the traditional symbol of Christian faith. This cross has an Alpha-Omega symbol at the bottom.
Latin
The Latin or Christian Cross is the most common form of the cross. The simple design is one of the oldest symbols of Christianity.
Lily
The Lily Cross is simply a Latin cross decorated with lilies–usually white arum lilies.
Maltese
A cross with arms of equal length that broaden from the center and have their ends indented in a shallow V-shape. The Maltese Cross is a symbol of protection. Sometime around the 11th or 12th centuries, the Maltese Cross began its rich history when it was awarded to a group of brave fighting men known as “The Knights of Malta.”
Mariner
The Mariner’s Cross looks like a Latin Cross/Anchor combination. As shown on the left, it is the symbol for the Mariner’s Church.
The nautical image of an anchor gives the idea of navigation (through life).
Moline
The Moline Cross is one of the oldest heraldic variations of the cross. In heraldry, the arms of the cross peal off into two curls at the end.
Russian Orthodox
The Russian Orthodox Cross consists of three bars, the lowest bar is slanted.
Swastika
The original swastika cross was a symbol of good fortune.
Unfortunately, the swastika is now associated with Hitler and evil.