Actually, to be more correct, it depends on what part of the world you are in on what it is called. Most widely known is pentagram and when upside down called an inverted pentagram. Call it what you like as neither is incorrect, as long as you do not turn it upside down.
In Wicca and the Neopagan faith, a 5 point star alone (without the circle around it) is called a pentagram. A 5 point star with a circle around it is called a pentacle. The 5 points represent Earth, Air, Fire, Water and Spirit. Here's more info: http://members.shaw.ca/bbogdan/blog_images/wicca/pentacle.htm
The four elements of Earth (green), Air (yellow), Fire (red), and Water (blue) are represented by the 4 lower points of the star. The upper point represents the Spirit. Spirit not only of Mother Earth and the Goddess but also the Spirit of the person wearing or using the star. Please keep in mind that not all information found on the internet is correct, although about 95% is. With all the discussion on what the star should be called maybe I should have thought twice before posting it as an auction. I have others but will NOT be posting them here.
my pentagram 24/7 and have 3 of them tattooed. have researched and have found that it can be called many things. I will not argue what you may call it. I wish only to be sure that it will be upright with top point of star pointing to Spirit.