If you're stuck, and in need of an all-physical, zinc-oxide-only sunscreen that you'll use up in a couple of weeks max: worth a try. It's not bad, by any means; it's perfectly usable for some purposes. Hence a 3. But it's not in the same league as the best all-zinc sunscreens out there, some of which are, yes, as "green," "natural," etc. as this one.
PROS:
---unscented, and didn't irritate.
---good as an eye-area sunscreen. If you’re looking for an all-zinc oxide sunscreen that’s very moist, but not utterly minging, this would be a good one.
---also decent on body; easy to apply, as it's quite fluid. Admittedly, I have dryish skin and my regular sunscreens can be on the thicker side (Blue Lizard, Vanicream).
---nicely moist, without being greaseball spectacular: not a common thing in all-zinc sunscreens, apart from the unwearable greasy super-squeaky-green kind that the EWG loves. Great on small children, not so hot on, errm, anyone above the age of reason let alone adults above the age of consent...
---did the job: protecting from burning; and fairly sweatproof and rainproof.
---cruelty-free
---FWIW: also using plant-based ingredients as much as possible, organic, hand-made by everyday sorts of people in the USA, etc. (*shrug* just saying, for the record, and as these are attractive factors for some MUAers; do with this information as you will, not necessarily my thing.)
CONS:
---Not as fine and sleek a texture as BurnOut or my other current experiment, the two ECO Logical ones
---not going near my face (see ingredients at end of review); patch-tested, zit started within minutes, off the Prairie came. Now: I'm sensitive and dryish. Warning, this stuff might be a possibility for people with seriously dry skin, but there's a very high risk it would be a nightmare in a bottle for anyone else's faces.
---no preservatives, and not because this stuff's been specially formulated without them. As others below report: goes off very fast. That's not a good idea for skin products. Especially around the eyes.
---not as water- and sweat-proof (so: not as reliable in serious sun and weather) as Blue Lizard, Vanicream, BurnOut Ocean Tested, or Eco Logical.
---some yummy-mummy fear-mongering soppy greenwash nonsense on the manufacturer's site (they do like the EWG: need I say more?).
Price: around about $12.50-17.00 for 5 oz, $23.00-26.00 for 9.5 oz. Decent and middle-of-the-road for this sort of sunscreen.
INGREDIENTS: Active ingredient: 20% micronized zinc oxide. This is in the form of coated micro Z-Cote, so containing other things too besides the ZnO.
Inactive ingredients: aqua (water), organic cold pressed olea europaea (olive) fruit oil, hamamelis virginiana (witch hazel) kosher vegetable glycerin, organic cocos nucifera (coconut), Behentrimonium Methosulfate, Cetyl Alcohol, Butylene Glycol organic, butyrospermum parkii (shea butter), organic theobroma cacao (cocoa butter), organic jojoba oil, rosemary extract

Oy is this horrible on so many levels. While it has great and advanced zinc filter in high amount, it's basically a white (as in BLUE WHITE) grease ball. Everything sticks to skin when I use Purple Prairie. And I have a cat. So cat hair sticks to my skin. Every dirt particle, sand, pollen, dust, hair, it all seems to fly in my direction like I'm a walking dirt magnet. It's gross. The finish, if you can call it that is 'oil slick'. No absorption into skin, not after 20 minutes not at the end of the day. Doesn't seem to adhere to skin very well either and doesn't look like it's water/sweat resistant at all. Can't even use it around the house on face because it clogs pores like mad (I'm guessing it's the coconut and olive oils), 2 days of using it and I have a 300% increase in blackheads. No good for hands either, I can't touch anything due it it leaving greasy+white fingerprints all over the place.
I'm not dissing cheap skin care per se, but in this case you definitely get what you paid for.

I asked my friend in Minnesota to send me a tube of this after seeing it earned EWG's top rating for sunscreen lip products. And it's okay. I didn't like it, but it's decent.
Pros: Excellent sunscreen protection, nice packaging, moisturizing, safe ingredients.
Cons: Doesn't absorb well at all, can't wear it under makeup. Like all sunscreens based on zinc oxide, this WILL give you the white jizz lips of doom. Also, the smell is kind of plasticky and strange. Nothing unbearable, but it lingers. [Edit: really short shelf life too.]
I use it when I go swimming in my building's pool alone, or if I'm hanging outside with my family. I wouldn't wear it in public though, because of the whiteness factor. It just looks clownish. If you don't mind looking a little silly and want an organic SPF lip balm with non-toxic ingredients, I say go for it and give this a try.

The only thing that prevents me from using this is I can easily take it off just by touching the skin (not even rubbing it) no matter if I've been wearing it for a half-hour or four hours. If I just touch the skin, my finger tip is covered in sunscreen. If it didn't come off so easily, I would continue to use this because it has 20% non-nano Z-cote and is completely nontoxic. There are a couple of other issues that don't put me off the product but I'll mention them anyway. I think it would be better if the packaging was opague and if this ss had a nontoxic preservative.
********UPDATE*****I woudn't use this because it lacks preservatives. I opened the lip spf for the second time about a month after receiving it and it smelled spoiled.

REALLY love this sunscreen!!!!!!
I've been looking for a zinc oxide based sunscreen that did not leave me looking like a mime...lol....and did not contain nano zinc oxide. Nano (20-50nm particle size), while offering tremendous UVB protection, does not provide very good long wavelength UVA protection (360-400nm).
This sunscreen smells really nice while not being overpowering like others. Goes on with very little whitening effect. Some whitening is a good sign. Let's you know it's not nano and is doing it's job. Some kind of tint over the sunscreen may or may not be needed.
The size of the bottle and price are hard to beat anywhere.