Does it affect SEO? How to preserve original unicode symbol?

E.g. I want a page to be found by searching ❌ (u274c) symbol (in context with other words).
Currently I'm afraid that search engine sees only image and "x" from the alt (not the same unicode u274c, just "x", i.e. u0078).
I've tried replacing character in a .markdown file with html entity `❌` but it results in the same ``.
How to prevent conversion to g-emoji for better SEO results?