Ruby gem should be worn after consulting experienced astrologer because gemstone does not give ill effect. But it acts like the representative of corresponding planet so it will work depending upon the placement of planet in birth chart.
A ruby with many flaws or impurity may cause trouble to the wearer.
In case the stone is in dusty appearance may cause stomach problem or childlessness
sometimes it is noticed that the stone temporarily loses its color, then the wearer may suppose to getting some problem and it regains its color automatically once wearer overcome the problem.