This is an easy way to make an altar pentacle.
A large pillar candle holder, made of any material. It should have a ridge along the outside to hold the candle. A flat candle holder will not hold the glass. (See Photo Below)
Circle of glass to fit the candle holder
Drawn/painted pentacle design to also fit inside the candle holder
How To Put It Together:
If the candle holder is wood, you may paint and decorate as you wish.
Take the candle holder to your local glass company. Have them cut a piece of glass to fit into the top of the candle holder. Have the edge of the glass ground so it isn't sharp.
Insert the drawn/painted penticle design into the indented part of the candle holder.
If you have a graphic program such as Paint Shop Pro or PhotoShop, you may design a pentacle graphic in it, such as GreyWing has done. Get as creative as you want with the design. Cut out the design after printing it and insert it into the indented part of the candle holder.
Place the glass over the artwork in the candle holder.
You have now created your own altar pentacle.