Our circa is based on the popularity of the marquise cut as the primary stone. The sapphire is a lovely color having that popular Ceylon blue coloration. It has no chips or cracks and is very clear. The jeweler took care with it's mounting as the prongs are at the end points-the most fragile part of the cut. We are calling it synthetic as it was quite common for 10K rings to not use the more expensive natural gems as the primary stone. The sapphire has not been tested. The faceted marquise is an approx. 10mm x 4mm & the natural diamonds are an approx. 2mm & 2.5mm. The mounting is quite attractive with recessed accent lines giving the sapphire the illusion of a flower and the diamonds as buds amid stems and leaves. The ring is nicely in round with fair density at back of band. There are no visible company or purity marks. But I do see what is probably the bottom portion remains on the interior of the band. The ring has been acid tested & Rich will guarantee a minimum of 10K. The ring weighs 3.4 grams with the stones in place in the mounting. A lovely ring for every day for that petite hand or teenager who appreciates vintage jewelry.