alexandrite

As nouns the difference between alexandrite and garnet

is that alexandrite is while garnet is (mineral) a hard transparent mineral that is often used as gemstones and abrasives or garnet can be (nautical) a tackle for hoisting cargo in or out.

As an adjective garnet is

of a dark red colour.

is likely misspelled.

has no English definition.

As a noun alexandrite

is a form of chrysoberyl that displays a colour change dependent upon the light source, along with strong pleochroism.

As nouns the difference between alexandrine and alexandrite

is that alexandrine is a line of poetic meter having twelve syllables, usually divided into two or three equal parts while alexandrite is a form of chrysoberyl that displays a colour change dependent upon the light source, along with strong pleochroism.

As an adjective Alexandrine

is belonging to Alexandria; Alexandrian.

As nouns the difference between pleochroism and alexandrite

is that pleochroism is (physics) the optical phenomenon in some colored, transparent crystals (such as tourmaline) in which the color is different in different directions while alexandrite is .

In mineral terms the difference between chrysoberyl and alexandrite

is that chrysoberyl is a vitreous mineral, often pale green, a mixed oxide of aluminium and beryllium with the chemical formula BeAl₂O₄, used as a gemstone while alexandrite is a form of chrysoberyl that displays a colour change dependent upon the light source, along with strong pleochroism.