If 2 vowels were together they are dipthongs so what consonants called?

There isn't a specific term for consonants that occur together in a similar way to diphthongs. Here's why:

* Diphthongs are about sound, not letters: A diphthong is a single vowel sound that starts at one point in the mouth and glides to another. This happens because of the way our vocal apparatus moves, not because two separate vowels are written next to each other.

* Consonant combinations are more complex: Consonants can combine in various ways, forming clusters, blends, or digraphs. These combinations can change the sound of the consonants involved, but they don't necessarily follow a consistent pattern like diphthongs.

Examples:

* Consonant Clusters: "str" in "street," "th" in "think," "tch" in "catch."

* Consonant Blends: "bl" in "blue," "fr" in "friend."

* Consonant Digraphs: "sh" in "ship," "ch" in "chair."

So, while there's no single term for consonants that combine in a similar way to diphthongs, the combinations are important and have different ways of being categorized.