this weighs 325g and its 95% pure gold
and its pretty close to 5cm high, 1cm thick and the circumference for it is of approximately 30 cm
source http://vikingmetalwork.blogspot.com/2013/02/ring-bling-huge-viking-gold-arm-ring.html
if we have two of them it will be more than, 5cm high, 1cm thick and the circumference for it is of approximately 30 cm
and it will weigh 650g
add another one and and it weighs 975g still less than a kilo
Style: Bangle
Color: Yellow
Metal: 14k yellow gold
Finish: High polish
Metal weight: 0.74
Bracelet dimensions: 4 mm wide x 8 inches long
source - http://www.overstock.com/tl/Jewelry-Watches/14k-Yellow-Gold-4mm-Polished-Bangle-Bracelet/9648494/product.html?refccid=76T4WNUN4GVIFKKBM3RYOZ4QJA&searchidx=0
so yeah youre prolly using the wrong equation for jewelry weight