Glossary
Plain-language definitions of the astrology, astronomy and gemstone words used across Star Gem Daily.
- Ascendant (rising sign)
- The zodiac sign and degree rising on the eastern horizon at the moment and place of birth. It changes about every two hours and needs an accurate birth time. Read more
- Aspect
- An angle between two points in a chart, such as a trine (120 degrees) or square (90 degrees), read as a relationship between them. Read more
- Birth chart (natal chart)
- A map of where the Sun, Moon and planets were along the zodiac, and which signs were rising and culminating, at a person's birth. Read more
- Birthstone
- A gem associated with a birth month, following the list American jewelers adopted in 1912 and have updated since. Read more
- Cusp
- The boundary between two signs or two houses. People born near a Sun sign change are often said to be born on the cusp. Read more
- Ecliptic
- The Sun's apparent yearly path against the stars. The zodiac is this circle divided into twelve 30-degree signs. Read more
- Element
- One of four groups (fire, earth, air, water), each containing three signs that share a temperament in astrological tradition. Read more
- Ephemeris
- A table of the positions of the Sun, Moon and planets at regular intervals. Astrologers and astronomers both use them. Read more
- House
- One of twelve divisions of a birth chart, each tied to an area of life such as home, work or partnership. Read more
- Illumination
- The share of the Moon's visible disk lit by the Sun, from 0 percent at new Moon to 100 percent at full Moon. Read more
- Midheaven (MC)
- The point of the ecliptic crossing the meridian, highest in the sky, at birth. Astrologers link it with career and public life. Read more
- Modality
- One of three groups (cardinal, fixed, mutable) describing how a sign acts, from starting things to sustaining them to adapting. Read more
- Mohs scale
- A 1-to-10 scale of mineral scratch resistance, from talc (1) to diamond (10). It ranks hardness but is not evenly spaced. Read more
- Retrograde
- The apparent backward motion of a planet against the stars, seen from Earth when Earth overtakes it or it overtakes Earth. Read more
- Ruling planet
- The planet traditionally associated with a sign, such as Mars for Aries or Venus for Taurus and Libra. Read more
- Station
- The moment a planet appears to stop before switching between direct and retrograde motion. Read more
- Sun sign
- The zodiac sign the Sun was in at your birth, the sign used for daily horoscopes. Read more
- Synastry
- Comparing two birth charts to describe a relationship in astrological terms. Read more
- Synodic month
- The time from one new Moon to the next, about 29.5 days on average. Read more
- Tropical zodiac
- The zodiac measured from the March equinox point, used in most Western astrology. It has drifted from the constellations of the same names over the centuries. Read more
- Whole sign houses
- A house system in which the rising sign is the whole first house, the next sign the second house, and so on. Read more