Context: 

As part of his first state visit to the United States, the prime minister gifted US President with an exquisite sandalwood box, a first edition print of the book The Ten Principal Upanishads from 1937, and a 7.5 carat lab-grown diamond.

Kar-e-kalamdani:

• The diamond was gifted in a papier mâché box. 
• Known as kar-e-kalamdani, Kashmir’s exquisite papier mâché involves sakthsazi or meticulous preparation of paper pulp and naqqashi, where skilled artisans paint elaborate designs.

About Lab-Grown Diamonds (LGDs):

• Definition and Distinction: LGDs are diamonds produced using technology that replicates the natural diamond growth process.
  • Unlike ‘diamond simulants’, LGDs are chemically, physically, and optically identical to natural diamonds.
  • Materials such as Moissanite, Cubic Zirconia (CZ), White Sapphire, YAG, etc. are “diamond simulants” that simply attempt to “look” like a diamond.
• Production Methods:
  • The most common method is High Pressure, High Temperature (HPHT), using extreme pressure and temperature to convert carbon into diamond.
  • Other processes include Chemical Vapour Deposition (CVD) and explosive formation that creates what are known as “detonation nanodiamonds”
• Environmental and Social Benefits:
  • LGDs can be produced using renewable energy sources, making them more environmentally friendly than mined diamonds.
• Properties and Applications: LGDs have similar properties to natural diamonds, including optical dispersion and hardness.
  • Their properties can be optimized for specific applications, such as industrial use as cutters and heat spreaders in electronics.

News Source: Indian Express