Arrested Development fans might laugh at the mention of diamond powder in skincare, but as it turns out, this ingredient is no joke. Literally made of finely-crushed diamonds, diamond powder has been turning up as an ingredient in skincare, haircare, and even dental care products–from serums and highlighters to tooth-exfoliating scrubs.

Products that contain diamond powder are likely to come with eyebrow-raising price tags–but do they live up to the hype? As skeptical consumers, we set out to discover the truth about diamond powder: How effective is it? What kinds of claims are made about it, and are they true? Most importantly, is it safe for use?

Benefits of diamond powder

Diamond powder is often found in two different types of products: Exfoliating skin products, and luminizing makeup and hair products.

Does diamond powder exfoliate your skin? There’s no reason to doubt the claims that diamond powder can exfoliate your skin. Crushed to a very fine grain, it can be a gentle and effective exfoliant. However, just because it works as an exfoliant doesn’t mean that it works better than any other exfoliating product out there. Skincare experts have suggested that the diamond powder craze is driven by consumers’ notions that the most expensive products are always the best ones. In reality, an expensive skin exfoliant with diamond powder is unlikely to be more effective than a comparable product that uses, say, rice powder as its base.

Does diamond powder make your skin glow? The answer here is: Yes and no. Diamond powder is highly reflective, so when it’s included as an ingredient in a highlighter or other makeup product, it will definitely create a shimmery, light-diffusing effect. You can also get this shimmery effect by using other, more reasonably-priced products such as this luminizer with crushed mica. Meanwhile, there’s no reason to think that diamond powder will make your skin glow in the long-term (after you remove that highlighter from your face). If you’re looking for a product that will give your skin a long-lasting, healthy glow, we recommend a natural vitamin-C serum or a resurfacing product with lactic acid.

Is diamond powder safe to use?

According to the Environmental Working Group’s Skin Deep database, diamond powder is safe for topical use. At least according to the research available, diamond powder doesn’t pose a risk of organ toxicity, endocrine disruption, cancer, or bio-accumulation. It doesn’t seem to have a negative impact on the environment, either.

Our verdict on diamond powder

The bottom line is that diamond powder is essentially safe for use, and some of the basic claims about its effectiveness are true. However, it can be all too easy to get caught up in the myth-making that surrounds luxurious, celebrity-endorsed skincare products (especially since advertisers can liberally mislead and manipulate us).

Diamond powder may be an effective exfoliating and luminizing ingredient, but at the end of the day, there’s no strong reason to choose products with diamond powder over products with comparable, but less expensive, ingredients.