For jew­el­ers, deal­ers and col­lec­tors alike, some of the big­gest chal­lenges are the same — and all too fa­mil­iar: How can one guar­an­tee the eth­i­cal prove­nance of a di­a­mond or pre­cious stone? #bitcoin #technology #computers https://t.co/eNzsSkdXyA