If you wish to use stones and crystals when laying out your circle or sacred space, you can use a mixture of both. You might mark each quarter with a large stone, particularly if you are outside, and then place other appropriate stones on top. Even if you use candles to mark the four quarters of the circle, you could surround or circle each candle with any or all of the following gems, either rough or polished:
North: moss agate, emerald, jet, olivine, salt, black tourmaline East: imperial topaz, citrine, mica, pumice
South: amber, obsidian, rhodochrosite, ruby, lava, garnet West: aquamarine, chalcedony, jade, lapis lazuli, moonstone, sugilite
Over time, gather a number of appropriate stones together. Beginning and ending in the north, lay out 7, 9, 21 or 40 stones of any size to define your circle. (These are magical numbers and will enhance the power, so always bear in mind the purpose of your circle.) If you normally use ribbon or cord to mark out your circle, your stones can be placed either inside the cord or ribbon or in place of it. If the magical working to be conducted within the circle is sending the power outwards, place any crystal with definite points facing outward. If the magic is of a protective nature, place them with points facing inward. Use your good sense when constructing your circle. If it is outdoors, somewhere you use often and think of as your sacred space, you may wish to leave the larger stones in position and carry the smaller gems with you. This way, no matter where you are, you can mark out a circle with the small stones and have available the power and energy of the larger space available to you.