A solid platinum and Iridium diamond ring.  This is a beautiful antique   The prong set total stone weight is approximately three quarters of a carat total and are approximately a VS clarity I colour stones.  They are lovely old cut stones, clean and bright.

The ring presents well and has the appearance of an eternity band once on the finger, it that traces the front of the finger with diamonds.  Only this example has about one third of the ring set with stones.  It is a fully hand made piece.  A lovely and charming antique ring.  The design tapers from a fine back to a slightly broader front.  This makes it comfortable on the inside of the finger.

The use of mixing these two metals was commonplace at the turn of the 20th Century. Typical alloy proportions are 90:10 or 70:30 (Pt:Ir). These have the chemical stability of platinum, but increased hardness. The Vickers hardness of pure platinum is 56 HV while platinum with 50% of iridium can reach over 500 HV. This improved hardness has also been considered as beneficial for use in platinum jewellery, particularly watch cases.  This made the metal quite hard to work with, but also allows it to be very durable.  Hence why this now one hundred year old ring still look good and retains its original shape and size.  Gold versions would have worn down considerably. 

The ring is stamped "plat Irid" and "hand made" using the human hand image. It is currently a US finger size 5.75.  It can be re-sized without issue.

Made in America, circa 1920's