RAPAPORT... Gemfields' earnings more than doubled in the first half of the year as the colored-stone miner returned to its usual auction cycle and demand strengthened.Net profit after tax came to around $56.7 million for the six months ending June 30, compared with $23.8 million a year earlier, the company said Monday in a trading update. Revenue from the Montepuez ruby mine in Mozambique rose 62% to $95.6 million, while sales from the Kagem emerald mine in Zambia soared to $85.2 million versus $31.2 million a year before.The Covid-19 pandemic affected Gemfields' auction calendar, with the company holding no ruby sales between December 2019 and March 2021. The supply of emeralds from Kagem also tumbled during the downturn."2022 saw the group return to its normal auction schedule of two emerald auctions and one ruby auction in the first half of the year," the company explained. "Following on from the strong auction results in the second half of 2021, the auctions held in the first half of 2022 saw a continuation of the robust demand for colored gemstones, with record auction revenues and per-carat prices being realized."Revenues from Faberg?(C), Gemfields' retail brand, jumped 94% year on year to $9.5 million, reflecting stronger wholesale income and the sale of the Faberg?(C) X Games of Thrones objet egg for $2.2 million.Image: Rough rubies from the Montepuez mine. (Gemfields)