Where a Pentagram is a 2D drawing, a Pentacle is a 3D construction. It has been used in many religions as a symbol of protection against evil. It once represented the Five Wounds of the Christ, but this was replaced by the unfolded Cube of Saturn, with the Christ sacrificed onto it. Not many people understand that this is symbolic of failure.
If one looks at the Hexagram with lines drawn to the points, it looks like a Cube. This is the aforementioned Cube of Saturn, also known as the Black Cube. Christ was not called Jesus until the 15th century. Jesus means Je-Zeus. Many who are saying the name Jesus are really invoking the god Zeus, also known as Jupiter, or Zachariel.
So, for positive energy, one can make a Pentacle. This can be constructed using five cut twigs from a living tree. These can be joined using cotton string or wool. It can be quite tricky putting together. The twigs will have all five elements in them. Air, Earth, Water, Fire and Spirit. Spirit is the Aether. It will remain in the Pentacle as Magic.
A Pentacle can be used for Magic Spells but is best to just draw the Pentagram. This is Action and Intent. The real purpose for the Pentacle is to create positive energies and protection from evil or negative entities. It should always point upwards as this is a symbol of the Divine. Upside down is a symbol to the Undivine and unclean Spirits.