JCK Las Vegas can be a whirlwind of business and socializing. But sometimes events during the week strike a deeper chord, as when two speeches put a human face on the industry’s charitable efforts.At the Diamond Empowerment Fund’s May 2 “Diamonds for Good” panel, 21-year-old Democratic Republic of Congo native Joseph Munyambanza told of being forced to move into a refugee camp at age 6. Determined not to let his circumstances define him, he studied hard even though he often went for days without a meal.As a teenager, Munyambanza and some friends put together Cobras, a mentoring school