Fire Quartz is also known as Harlequin Quartz. It is a clear quartz with hematite inclusions. Often, this stone is heated after being extracted from the earth to enhance the red color in the stone. Ladies, you will find this a powerful stone to work with during menstation!
"Harlequin Quartz expresses universal love and acts as a bridge between the spiritual and physical worlds. With strings of red Hematite dots dancing within it, it stimulates healing the heart and draws physical and spiritual vitality into the body, providing inspiration. Balancing the polarities and meridians in the physical body, this crystal anchors them to the etheric to harmonize the subtle and physical nervous systems. Mentally soothing, it is an excellent stone for helping Indigo children adapt to being on earth." Judy Hall, The Encyclopedia of Crystals