All Zodiac Signs are grouped in to four triplicates based on their Ancient Greek elements that sustain a balanced life force.
The other triplicities are the Water Element Signs: Cancer, Scorpio and Pisces, Fire Element Signs: Leo, Sagittarius and Aries, and the Air Element Signs: Aquarius, Libra and Gemini.
Earth is real and natural. Earth is by definition grounded in the physical world. Earth can be touched and felt and will remain unchanged forever.
Earth element signs are the practical members of the Zodiac. Earth is reliable and never flighty. Earth signs remain calm even in the face of enveloping chaos. When the going gets tough, Earth signs are a rock on which others can depend to see things through to the end.
Earth signs are not seen as the most imaginative. Earth finds the solutions most likely work in the long run. They will look at each option in turn and go with the idea that looks most likely to succeed, rather than the most interesting path.
Earth signs are the ones who keep going until the end after others have given up and turned back. Give them a map and compass and rest assured you will arrive, although not always in first place.
If you are looking for a stable partner for life, someone who can be called on in good times and bad, have a long look at Capricorn, Taurus and Virgo.