Israeli Benny Landa is the founder of Landa Digital Printing (see here). His latest venture is Lusix, which makes quality diamonds of up to 3 carats from methane gas. His machines bond carbon atoms to a diamond seed at 5000 degrees C. The product is chemically identical to a mined gem.
https://www.calcalistech.com/ctech/articles/0,7340,L-3771457,00.html