Belgium's polished diamond exports rose 7.7 percent year on year in May to $1.271 billion, while the price per carat jumped 12.5 percent to $1,993, according to data collected by the Antwerp World Diamond Centre. However, polished diamond imports surged 27.9 percent to $1.314 billion, leaving Belgium with a net polished export deficit of $43 million compared with net exports worth $154 million in May 2012.

Rough imports fell 5.4 percent in May to $1.051 billion and rough exports increased 6.1 percent to $1.221 billion. The data resulted in a rough import deficit of $170 million during the month compared with a deficit of $40 million one year ago. Belgium's net diamond account for May, reflecting the net difference between exports and imports, plummeted to a deficit of $3 million compared with a surplus of $194 million one year ago.

During the first five months of 2013, Belgium has exported $5.778 billion worth of polished diamonds, up 1.4 percent year-on-year, while polished imports have fallen 2.3 percent to $5.542 billion. Net exports of polished diamonds totaled $236 million compared with only $24 million for the same period in 2012. Rough imports of $5.929 billion during the first five months reflected a 5.5 percent year on year increase, and yet rough exports have risen 6.3 percent to $6.333 billion, leaving an import deficit of $404 million compared with a deficit of $335 million.

Belgium's net diamond account for the January through May period improved 78.3 percent year on year to $640 million.