Necklace and pendant with blue topaz

Nacklace and pendant with faceted teardrop-cut blue topaz, approx. 12.5 x 9.5 mm, 18K white gold, 20.6 g, pendant: L x W: approx. 20.8 x 16.5 mm, eyelet D: approx. 3.2 mm, triple anchor chain L: approx. 39 cm, W: approx. 1.5 mm per strand, with carabiner and eyelet D: approx. 2.7 mm, 21st century, minimal signs of wear, with hallmark.