Emily Dickinson used three types of rhyme:
First is exact rhyme. Take the poem "Because I Could Not Stop For Death," for example. Examples of exact rhyme is me/Immortality in the first stanza.
She also used slant rhyme where the words "sort of" rhyme--they are close, but not exact. In the same poem, look at chill/Tulle and Day/Eternity.
She also uses what is called eye rhyme. In this type of rhyme, the words look like they SHOULD rhyme, but they don't. For example, in "The Soul selects her own Society", she uses One/Stone--the spelling leads one to believe they should rhyme, when in fact they do not (rough/dough--like that).
Emily Dickinson wrote almost 1,800 poems during her lifetime, so examining each one would require more time than we have here, but looking at even one of them shows that she used both exact rhyme and slant rhyme. Consider the first two stanzas of "I Felt a Funeral, in my Brain," for instance:
I felt a Funeral, in my Brain,
And Mourners to and fro
Kept treading--treading--till it seemed
That Sense was breaking through--
And when they all were seated,
A Service, like a Drum--
Kept beating--beating--till I thought
My Mind was going numb--
In the second stanza, "Drum" and "numb" rhyme perfectly to the ear (exact rhyme). In the first stanza, "fro" and "through" are close in rhyming, but they do not rhyme exactly. Therefore, they compose a slant rhyme, sometimes called "off rhyme" or "approximate rhyme."
There may be Emily Dickinson poems out there somewhere that do not rhyme at all, but I've never read one.
Most often, Dickinson uses exact rhyme, though she has been known to use slant rhyme as well. As an example:
Because I could not stop for death
He kindly stopped for me,
The riders were but just ourselves
In this excerpt, we see that "death" and "ourselves" both use the short "e" sound toward the end of each word, making a sort of slant rhyme, but more evident is the exact rhyme of "me" and "immorality." Another device to consider in Dickinson's poetry is its distinct meter. Almost every Dickinson poem can be sung to the tune of three songs:
The Gilligan's Island theme song
The Yellow Rose of Texas
This is a fun exercise to try, and it goes together well with examining Dickinson's rhyme scheme.