(IDEX Online)- Almost all jewelry retailers who sell lab-grown diamonds in the US say their margins are better than with mined gems. And more and more consumers are asking for them.Those are among the key findings of Gaining Critical Mass, a study by US-based MVI Marketing LLC (THE MVEye). Almost four out of 10 independent jewelers are sell lab-growns, says the report, and Signet, the biggest US chain, now stocks them."Lab-grown diamond is a high margin category that consumers are reacting to positively. Now that Signet is in it, other jewelers will have to take a hard look at this category or lose out on it," said CEO Marty Hurwitz (pictured).Headline stats from the research include:80% of jewelry consumers in 2020 have heard about lab-grown diamonds, up from 58 per cent in 2018.69% of jewelry consumers in 2020 knew of brands using lab-grown diamonds, up from 49 per cent in 2018.62% of lab-grown diamond retailers report that 5-50 per cent of diamond customers ask about lab-grown diamonds.Jewelers report a closing ratio of 60 per cent to 80 per cent once customers learn about the product, says the report. An estimated 38 per cent of independent retailers in the U.S. offering LGD in-store and/or online. THE MVEye forecasts that, by Holiday 2020, more than 50 per cent of independent jewelers will be on board. A majority of LGD retailers surveyed (61 per cent) expressed extreme satisfaction with the decision to stock and promote this product category. Ninety-five per cent retailers in the survey report better margins with lab-grown diamonds with 78 per cent reporting margins that were 16 per cent to 40 per cent-plus better than mined diamonds. The report, co-sponsored by the International Grown Diamond Association (IGDA) and Instore Magazine, is based on online studies and video interviews with over 1,000 consumers, and one-on-one evaluations of jewelry retailers.