Mold can grow inside it, because those cracks in the glaze let moisture and skin cells down into the bisque of the tile body. Never put it in a wet area.

A big no

Find somewhere else to use the tile you love. Showers can sometimes have issues ... no need to increase your odds by using a tile that is not rated for wet areas.

I think you rather answered your own question? : )

You might show the bath, the crackle tile, and the rest of the materials in the bath?

@JAN MOYER, @chispa, @Patricia Colwell Consulting, @Monique. I thought about starting a new thread as I don't mean to highjack, but perhaps it's better to also address ceramic tiles here, under this crackle post.

Do you recommend avoiding ceramic tile in shower installations and use porcelain exclusively, or is ceramic a viable option when installed correctly?

ETA what about glass tiles?

Ceramic has been used for hundreds of years. What do you think all the 80 year old pink and blue bathrooms are built with?

^^

What she said

@Monique that made me lol.

@JAN MOYER agrees which makes me think maybe I'll give ceramic a whirl.

I found a 3x12 Ceramic Marazzi for shower walls that are perfect for my project, great price point, and in stock.

Not rectified

Water Absorption ASTM C373 < 20.0

https://s7d9.scene7.com/is/content/daltile/MZ_CostaClara_SSpdf

Rolling the dice or good to go?

A regular ( even a boring basic ) ceramic tile, cheapest of cheap , any shape, does NOT absorb water. How many ways can we say it?! : )

Go to a big box, buy the single cheapest box you can find, stick it under a running water stream and watch the water!

What makes crackle bad is what everyone has stated. It is essentially.........POROUS.

I’ve used Costa Clara in multiple projects. As long as it‘s a standard homeowner shower, and not a locker room steam room, it's fine. Find an installer who understands TCNA install methods, and it is all good.