Gender of Russian nouns

1) There are very few exceptions to these rules. But there are five notable exceptions, this occurs mainly because of physical gender.
па́па – (daddy, father) – masculine
дя́дя – (uncle) – masculine
де́душка – (grandfather) – masculine
мужчи́на – (man) – masculine
ко́фе – (Coffee) – masculine

2) Nouns ending in “мя” are neuter.
вре́мя – (time)  – neuter
се́мя – (seed) – neuter
пле́мя – (tribe) – neuter
и́мя – (name) – neuter

3) With the nouns ending in “ь” there are no reliable ways of predicting the gender. These are the only nouns where you have to learn the gender, but they are a small group.

For example, the following nouns are masculine:
автомоби́ль – car, motor vehicle
гость – guest
день – day
портфе́ль – briefcase
шампу́нь – shampoo
слова́рь – dictionary
дождь – rain
карто́фель – potatoes
рубль – rouble
у́голь – coal

The following nouns are feminine:
дверь – door
ло́шадь – horse
соль – salt
цель – goal, aim
кость – bone
ме́бель – furniture
роль – part, role
цепь – chain
пыль – dust