Clinker shows damage

Never show.

1) Judges hate unreasonable wars of attrition
2) a criminal proceeding does not bring you damages, you will have to sue privately anyway
3) the two proceedings can block each other, you will be dependent on the work of the public prosecutor
4) a destroyed opponent can no longer pay you money

There is a difference between selling and delivering. Was a wrong brick really sold or was it just delivered incorrectly? If you cannot prove that it was sold incorrectly, I would refrain from pressing charges.

Under no circumstances report it.

1) Judges hate unfounded wars of annihilation
2) a criminal proceeding will not bring you compensation, you will have to sue privately anyway
3) the two proceedings can block each other, you will be dependent on the work of the public prosecutor
4) a destroyed opponent can no longer pay you money

perhaps threaten indirectly with it?

There is a difference between selling and delivering. Was a wrong brick actually sold or was it just delivered incorrectly? If you cannot prove that a wrong sale took place, I would leave the criminal complaint alone.

Exactly the stone was sold and delivered to me, but it is not clinker....therefore it is not a wrong delivery. The seller has his own designation, the wholesaler also has his own designation for the stone. I received the technical data sheet from the seller, where the model designation of the wholesaler is adopted and it is also not defined as "clinker" there!

You did not want your house to be simply wrapped in a non-load-bearing interior wall made of exposed brick masonry, but you wanted clinker brick. If you ordered one thing and received and were charged for another, that is fraud. This is objectively the case insofar as the two things can be distinguished from each other. Clinker is to brick as rusk is to toast, or as Wikipedia explains:
Klinker are bricks that have been fired at such high temperatures that the beginning sintering process closes the pores of the firing material. Clinker absorbs hardly any water and is very durable. The name can be etymologically traced back to the fact that striking hard-fired bricks/clinkers together produces a high-pitched sound. In the past, clinker was also referred to as Hartbrandziegel.

I consider the clear objective distinguishability, regardless of how the dealer names the product, sufficient to successfully pursue your claims. But I can hardly dismiss the concern that civil and criminal proceedings can mutually slow each other down in a dual-track process.

The higher water absorption capacity of facing bricks compared to clinker bricks is mainly due to the raw materials and is therefore a characteristic product property that should by no means be considered as a reduction in quality. In the relevant standards and especially in DIN 1053-1, no differentiation is made regarding the suitability of facing bricks and clinker bricks for the facing shells. cf. [Webseite der Ziegelindustrie].

I wouldn't be so sure that you would succeed in having your demands accepted with the argument that facing bricks are unsuitable.

"The higher water absorption capacity of facing bricks compared to clinker bricks is mainly due to raw materials and is thus a characteristic product property that should by no means be regarded as a reduction in quality. In the relevant standards and especially in DIN 1053-1, no differentiation is made regarding the suitability of facing bricks and clinker bricks for the facing shells." see the website of the brick industry.

I would not be so sure that you would get your demands through with the argument that facing bricks are unsuitable.

I immediately disagree with that......

You can drive with a petrol and diesel car......the question is, you want a diesel and then get a petrol, then no judge can say; "Why a problem, both drive?!."

As a buyer, I wanted a clinker and nothing else, it's not about "suitable or unsuitable" for me.