https://en.m.wikipedia.org/wiki/Burial_ritual
- Cremation is the incineration of the remains. This practice is common amongst Hindus and is becoming increasingly common in other cultures as well. If a family member wishes, the ashes can now be turned into a gem, similar to creating synthetic diamonds

From Ashes To Ashes To Diamonds: A Way To Treasure The Dead
Most of the diamonds synthesized from cremated remains come out blue, due to trace amounts of boron in the body. These diamonds, made from the ashes of animals, were created through the same process used to make diamonds from human remains.
Courtesy Rinaldo Willy/Algordanza
Diamonds are supposed to be a girl's best friend. Now, they might also be her mother, father or grandmother.
Swiss company Algordanza takes cremated human remains and — under high heat and pressure that mimic
conditions deep within the Earth — compresses them into diamonds.
Rinaldo Willy, the company's founder and CEO, says he came up with the idea a decade ago. Since then, his customer base has expanded to 24 countries.
Each year, the remains of between 800 and 900 people enter the facility. About three months later, they exit as diamonds, to be kept in a box or turned into jewelry.
Most of the stones come out blue, Willy says, because
the human body contains trace amounts of boron, an element that
may be involved in bone formation. Occasionally, though, a diamond pops out white, yellow or close to black – Willy's not sure why. Regardless, he says, "every diamond from each person is slightly different. It's always a unique diamond."
Most of the orders Algordanza receives come from relatives of the recently deceased, though some people make arrangements for themselves to become diamonds once they've died. Willy says about 25 percent of his customers are from Japan.

(website called npr)