This image is a crop of both the full length image of Katherine Mackay (Katherine Alexandra Duer (US1797spouse1)) and the crop of that full length image of her. As can be seen from the caption accompanying this image, it shows the demi-parure of emeralds as well as the diamond pendant at the end of her chain.
The caption accompanying this image reads:
Mrs. Mackay's demi-parure of emeralds was certainly along royal demensions [sic], as was the diamond pendant at the end of her chain.
Obviously, the word "demensions" is a typographical error that should be "dimensions" instead.
See Harbor Hill, Clarence Hungerford Mackay's Mansion.
