The celtic knot is an ancient symbol of the journey of life. With no beginning and no end, the knot represents the timeless nature of our spirits and the world we live in. A Ruby celtic knot combines these concepts with the spiritual attributes of the Ruby . Gem of hot summer nights and steamy red sunsets, ruby is the birthstone of July. Show the world the passions within you with a fiery ruby ring. Once considered more valuable than diamonds, a peridot ring is a must have. This "gem of the sun" is the birthstone of August and is a beautiful match for the lush green tapestry of late summer.