Ring

Featuring a central dark, rectangular gemstone surrounded by a halo of smaller, clear stones, likely diamonds or cubic zirconia. The ring's band appears to be made of a gold-toned metal, possibly rose gold or yellow gold. 
To extract a description of such a ring, one would typically focus on the following characteristics:
Gemstone Type and Cut:
Identify the main gemstone  and its cut (e.g., emerald cut). 
Color and Clarity:
Note the color of the main stone (e.g., black) and the clarity of any surrounding stones. 
Metal Type:
Determine the type of metal used for the band and setting (e.g., gold, silver, platinum) and its color (e.g., rose gold, white gold). 
Design Elements:
Describe the overall design, such as the halo setting, the presence of side stones on the band, or any vintage characteristics.