Set in September 2018, the case describes De Beers’ attempt to halt the escalating disruption to its core business posed by diamonds grown in laboratories. Since its inception over a century ago, De Beers had created and nurtured the perception of diamonds as rare objects and exclusive symbols of love. But lab-grown diamond makers now had the capabilities to mass-produce and sell at a discount diamonds with the same optical, chemical and physical characteristics as natural ones, possibly jeopardising the entire mined-diamond industry. To counter the threat, De Beers introduced its own lab-grown diamond jewellery brand, called Lightbox. Lightbox diamonds were positioned as cheerful fashion items and sold directly to consumers at a substantial discount to generic lab-grown diamonds. Over its history, De Beers had had a remarkable track record of dwarfing competition. Would it succeed this time?