Actually, it's hardly a challenge ^.^ Because Japan and South Korea has been making mineral sun protection powders in both loose and compact forms since, like, the mid 2000's. Check cosme.net for the Japanese ones if you don't believe me, I don't read Korean so I don't know of an equivalent reference. Anyway, when it comes to loose or compact powders, you have a whole spectrum that spans from a base makeup powder with a tiny bit of [pathetic] sun protection to a more serious sunblock powder with or without any color.
This 5g jar of UVLab Mineral Powder SPF50 PA+++ would be the latter, a physical sunblock powder without any color at all.
You've probably noticed I use the word "sunblock" to describe some of these powders, instead of "sunscreen." This is because "sunblock" refers to broad spectrum protection against both UVB (as indicated with the SPF rating) and UVA (as indicated with the PA rating). The American FDA banned the commercial use of the word "sunblock" on product labels because it was misleading, giving consumers an exaggerated sense of protection when most US-made sunscreens frankly provide subpar UVA protection, and thus not "broad spectrum" as a sunblock should be. Instead, starting 2012 the commercial use of "broad spectrum" on product label = a UVA protection "proportional" to the UVB's, whatever the hell that means. This is why I stay far away from the US-made products and stick with the European or Asian-made ones instead, because the ratings are somewhat clearer and at least you kind of know what you're getting ^.^"
In the case of UVLab Mineral Powder, it was released February 2013, one month after revisions of the Japanese UVA protection ratings went into effect. Under this new system, a rating of PA+++ = PPD 8-16, which is pretty good, so in my humble opinion it qualifies as a sunblock powder. The main ingredient is Titanium Dioxide (酸化チタン), a physical UV filter (and admittedly weaker than zinc oxide in filtering UVA) with concentration unknown. The powder is free of colorant, fragrance, alcohol, and mineral oils.
So I should really thank my sis-in-law for this brand new obsession (...or not LOL!). I've been hunting down all the mineral sun protection powders I could get my grubby hands on, the higher the protection the better. And in my search I have a strong preference for loose powder over pressed. The reason being I'm already wearing a sunscreen milk as makeup base (my trusty Allie, in the new formulation with SPF50+ PA++++), then a tiny bit of BB cream as concealer which may or may not have any SPF, then I set the whole thing with loose powder. So you see, loose powder is already an important step in my makeup routine. And if I'm going to use a loose powder either way, why not go for those that provide some sun protection? While this sounds like a no-brainer, I never even thought of it!
These sun protection powders have many more benefits than simply setting makeup. If I'm lazy enough, I'd skip the makeup altogether and use this powder to set my milk sunscreen instead, dusting it on my neck, décolletage, and arms afterwards. If you're living in a humid environment, many of these loose sun protection powders provide excellent sebum and shine control also. No need for oil blotting sheets anymore - just dust these on and get extra sun protection to boot! In Japan, they sell these moist "powder" sheets. As in you use the sheets to wipe off sweat and freshen up, and these sheets would leave behind a thin layer of powder that give the skin a dry finish and free your neck, décolletage, and arms of sticky-icky sweat.
As you can see, this UVLab Mineral Powder is colorless and is pretty much a baby powder with sun protection ^.^ It looks opaque in the swatch picture, but after blending out it's translucent. That said, on the face it leaves a very slight white case, so for facial use it's probably more suitable for those with fairer skin. On the body I don't give a rat's ass about the white cast ^.^ Also, I don't use the puff and use my own brushes instead. For facial application, I use my big fluffy goat hair brushes. For body application I use The Body Shop synthetic kabuki brushes instead.
This is the bareMinerals SPF30 Natural Sunscreen that started it all ^.^