A different process, which involves heating natural gas and hydrogen under high pressure, has also been invented, allowing one to make diamonds up to four carats in size. But for this method you need a huge compressor (as big as half a house), growth is slow, there are impurities, and production costs are excessively high.
此外，利用高溫高壓法加熱天然氣和氫氣，也可以做到 4 克拉大的鑽石。這種方法的缺點是要用很大的加壓機，生長慢且有雜質，成本也過於昂貴。