Reports from September’s Hong Kong fair reflect a slowing, bifurcated marketWith retail forecasters calling for a bright holiday season and pundits heralding the return of the middle-market consumer, reports of sluggish sales from the September Hong Kong Jewellery & Gem Fair are striking a contradictory note, with buyers seemingly split between the low and high ends of the market.By all accounts, high-end jewels, designer offerings, and color did the best; midrange jewelry and white diamonds failed to meet sales expectations. Sapphires were the big winners, followed by unheated Mozambique ruby and red spinel. Other top sellers included large tourmalines (particularly green, rubellite, and Paraiba varieties), ­tsavorite and spessartite garnets, and fine aquamarine. “Demand is for one-of-a-kind, high-value stones,” said Shaun Ajodan of New York City’s Shaun Gems.Hawaii-ba