Leslie Blodgett was in no doubt when she joined the San Francisco-based Bare Escentuals as CEO in 1994 that she could start a cosmetics revolution. Out of rocks.

Some might have said she had rocks in her head, but Blodgett knew otherwise. She took the company’s existing low-key mineral make-up range and “brought it up to speed” — the result, the BareMinerals range, now includes the bestselling foundation in America.

“The foundations on the market were unappealing: they felt horrible, made you look like you were caked in make-up and made your skin worse over time. Dermatologists would [often] tell people with skin issues to stop using foundation,” says Blodgett. However, with mineral make-up, she says: “There are fewer incidents of adult acne and skin problems, because our make-up is proven to improve your skin.”

She is not exaggerating. If you haven’t got into mineral yet, you might want to start now. Mineral foundation is like no other: it is made from ground-up rocks, contains no additives, has the appearance of a powder, and is literally brushed onto the skin. Products include foundation, bronzer, blusher, eye shadow and now lipstick. Advocates wax lyrical for hours about the advantages of it.

Take Susan Posnick, who has her own mineral range, and who stresses the good-for-you aspects of this type of make-up. “After being diagnosed with cancer, I wanted to use a product that would provide maximum sun protection, yet not feel heavy or like a mask on my skin,” she says.

“I also wanted a foundation that wouldn’t melt in the heat [like liquid foundation], yet would still give me a radiant complexion. Pure mineral make-up allows the skin to breathe, so it is the healthiest, most natural make-up you can apply.”

There are superficial benefits too, says Posnick: “It contains no fillers or powders, so it won’t settle into fine lines. The minerals respond to the warmth of the body to create a ‘second skin’ that makes your complexion fresh and luminous.” So you won’t look in a mirror in the middle of the day and feel as if your make-up has slipped down your face, highlighting every last little crinkle.

Terry de Gunzberg, make-up artist and creator of the By Terry range, says she has always used minerals in her products, but she just hasn’t mentioned them. “It has become a new trend and marketing claim, because mineral make-up today is more refined and lighter, and the range of colouring pigments is much wider,” she says. “What the cosmetics industry and customers appreciate is that it respects the skin, perfecting it instantly, and is easy to apply.”

For most, however, it’s the flawless finish and staunch hypoallergenic credentials that have them convinced. “Mineral make-up is kinder to the skin, less allergy-inducing and gives a natural, flawless finish, making it ideal for all skin types, particularly sensitive skin,” says Amanda Bel of the British brand Pixi. “And cosmetics companies have not, as yet, added perfume to their mineral powders and foundations, unlike normal foundations.”

So are there any doubters of the magical properties of mineral make-up? Some experts believe that it can be too drying to the skin, but they are in the minority. All this enthusiasm doesn’t mean that traditional foundation will soon be obsolete, however. “Mineral make-up is an alternative, and it’s great for people who want an easy solution,” says Nicky Kinnaird, the founder of Space NK.

So easy, in fact, that BareMinerals even boasts that it is so pure, you can sleep in it. “We were being ‘cute’ when we said that,” says Blodgett. But, it turns out, some of their customers even apply it just before bed as a treatment for skin problems such as acne.

No more bleary-eyed, late-night cleansing? Guilt-free blusher on the pillow? Now that really is a beauty revolution.

How does mineral make-up work?

Promising to improve your complexion, protect you from the sun and reduce the amount of chemicals permeating your skin (and damaging the ozone layer), mineral make-up claims to have it all. The key minerals found in the (refreshingly short) list of ingredients are titanium dioxide and zinc oxide — two of the most natural active ingredients in sunscreens. Plus, mineral make-up is non-comedogenic, meaning it won’t block your pores, but it will still provide flawless coverage.

Mineral make-up is a firm favourite with those who suffer from problem skin such as Cameron Diaz, not least due to the absence of perfumes and preservatives (most are also oil-, talc- and wax-free). Lynne Sanders, the founder of Cosmetics à la Carte, heralds it as “the answer to your prayers. If you have blemished skin, it provides oil-free, long-lasting coverage”. This optimum coverage is thanks to the light texture of the powder. “Even if you reapply, you’ll still see a natural, translucent radiance,” says Wilma O’Leary of Boots.

Creating mineral make-up is a painstaking process, which varies according to the brand, but most agree on the principle of mixing finely crushed minerals with water to form a thick paste. The new Mac mineral collection, Mineralize, is baked on terracotta tiles in the warm Italian sun for 24 hours — a far cry from the factories that produce most of the products in your make-up bag. The end result is a pure powder of microfine texture. Colour can be lent through the addition of another natural mineral, iron oxide.

So, does this mean minerals can only be used in powder formulations? The mineral-make-up pioneer Jane Iredale explains: “The right mineral liquid foundation can be just as effective as a powder in look, feel and coverage. But there is more opportunity for adding synthetics to a liquid because of the need to preserve it, although we have found ways to do this with natural ingredients.”

Brush up on your technique

There’s a certain knack to applying mineral make-up. Its superfine texture means it is trickier to distribute across the skin than other powders or liquid foundation. The secret is all in the tools. Mineral powders often come with their own brush — otherwise, invest in a good-quality soft goat-hair brush, not sable, which is slightly coarser. Start off with a Kabuki brush (top right). These are small enough to take out and about with you and are firm enough to control the amount of product you pick up.

Caroline Barnes, the Max Factor UK make-up artist, suggests using the side of the brush: “This helps to get into those tricky areas around the nose and hairline.” BareMinerals advises a “swirl, tap and buff” motion to sweep up the powder and press it onto the face in circular movements, a little at a time.

Joanna McGarry and Francesca White

Mineral magic: what we love

1 Cover FX Mineral FX Foundation in C40 £27, from Harvey Nichols. 2 Inika Lip Liner in Bordeaux £11; inikacosmetics.co.uk. 3 Jane Iredale Cream to Powder Eyeliner in Jewel Box £23; 020 8450 7111. 4 BareMinerals SPF15 Foundation in Golden Dark £17.50, from Selfridges. 5 Susan Posnick Colorflo mineral foundation £45; 020 8997 8541. 6 Mac Mineralize Skinfinish Powder in Gold Deposit £16.50. 7 Laura Mercier Mineral Eye Powder in Sapphire £8, from Selfridges. 8 By Terry Blush Expert Mineral Compact Brush £30, available October 15, from Space NK; spacenk.co.uk. 9 Glominerals GloEye Shadow in Berry £13; 0800 121 8116. 10 Laura Mercier Mineral Powder SPF15 in Classic Beige £30, as before. 11 Inika Mascara in Brown £14, as before. 12 BareMinerals Natural Lipcolour in Red Delicious £12, as before

Times recommends

• Live fashion advice: how to dress for party season
• The A-Z of winter style rules
• Could safe havens prevent teenage stabbings?