Star sapphires, including purplish-pink varieties, showcase a captivating optical phenomenon known as asterism. This effect manifests as a distinct, star-like pattern that seems to gracefully float across the surface of the gem when it is moved under a light source. The star pattern is formed due to the presence of tiny needle-like inclusions of the mineral rutile within the sapphire. When cut as a cabochon, with a smooth, rounded top and typically flat bottom, these inclusions reflect and scatter light, creating the illusion of a luminous star with intersecting rays. The purplish-pink hue of such a sapphire is rare and especially sought-after, providing a stunning interplay of color and light.
