It doesn’t sound natural. You link two different word groups (noun group + sentence) in a same sentence, so you should either transform a phrase or seperate them into two different sentences.

1. Produit naturel (,/et) décantation normale.
2. Ce produit est naturel. La décantation est normale.

The answer of Archa is good, however, I want to add a few elements :

• rather than doing two sentences, I would make one that explains the link between both : "the separation is normal because this is a natural product.."

• the word "décantation" does not fit with your explanation, it means that you have clarified the beverage conventionally. I would rather use "dépot" which means that there are some "sediments" in your bottle.

[10th meaning of Wiktionary –] Sédiment qu’un fluide dépose au fond du vase où il a séjourné pendant quelque temps.

• Il y a un dépôt au fond du vase.
• Un léger dépôt n’altère en rien la qualité de ce produit., phrase justifiante inscrite sur l’emballage de certains produits de commerce.

The last example in wiktionary perfectly fits what you need :

Un léger dépôt n’altère en rien la qualité de ce produit [naturel].

→The few sediments don’t degrade the quality of this [natural] product.

I added natural to match your original sentence.

EDIT : Since you are asking about a short translation and in comment it looks that you are not satisfied, I have to add this part to my original answer.

To fit literally your sentence :

Ce produit est naturel, la séparation est normale.

will sound perfectly correct in French, and will be understood in food context.

Then you can choose to add or remove some words :

• Ce produit est naturel, la séparation est donc normale.
• Ce produit étant naturel, la séparation est normale.

or (even if it doesn’t sound well because of reasons Archa gave but matches with your translation) :

Produit naturel, la séparation est normale.

or the shortest :

Produit naturel, séparation normale.