The magi's coming to Jerusalem in order to pay homage to the king of the Jews shows that they seek in Israel, in the messianic light of the STAR OF DAVID, the one who will be king of the nations. Their coming means that pagans can discover Jesus and worship him as Son of God and Savior of the world only by turning towards the Jews and receiving from them the messianic promise as contained in the Old Testament.- Catechism of the Roman Catholic Church
Historically speaking, the Catholic Church wasn't very prone to call the hexagram the Star of David (or Magen David in Hebrew). In fact, for several centuries before the modern term 'Star of David' ever became part of everyday vocabulary, and long before this symbol ever became specifically Jewish, the Church preferred to refer to the hexagram as the Star of Creation, or the Creator's Star. Now the obvious question that might come to readers' minds is why on earth did the Christian authorities ever refer to this symbol in such a manner. The Star of Creation? Whatever does that mean?
The six-pointed star is the Creator's Star or Star of Creation. Its six points stand for the six days of creation.- Christianity/symbols/6-point star, ReligionFacts.com
The easy answer is to simply point out that God's Creation includes both the Heavens and the Earth, Mountains and Valleys, Clouds and Seas, Volcanoes and Tornadoes, so the symbolic representation of BOTH distinctly different items placed together would of course signify the reality that Creation is filled with a diverse array of BOTH phenomenon- not to mention the fact that every snowflake is basically a Star of David, in one form or another.

All of this is true of course, but it doesn't really truly answer the question completely. Why not call it the God's Star, rather than the Creator's Star? Obviously, there must be a reason behind this particular designation and the following analysis of the Creation story in the 1st Chapter of Genesis (Genesis 1:1-27) is a humble attempt to explain the reasons why-
The Star of David seems to nest itself in the beginning of the Bible...
- The Star of David, by Frank Colijn, Members.home.nl
_________________________
(1)
In the beginning God created the Heavens AND the Earth./ The Heavens= Up Triangle --> 'God created the Heavens'
= The Earth= Down Triangle --> 'God created...the Earth.'
+ God's Creation= Star of David --> 'God created the Heavens AND the Earth.'

_________________________
(2)
The earth was formless and void, and darkness was OVER the surface of the deep, and the Spirit of God was moving OVER the surface of the waters./ Darkness= Up Triangle
= The Deep= Down Triangle
+ Darkness OVER the Deep= Star of David --> 'darkness was OVER the surface of the deep'
/ Spirit of God= Up Triangle
= The Waters= Down Triangle
+ Spirit of God OVER the Waters= Star of David --> 'the Spirit of God was moving OVER the surface of the waters.'
_________________________
(4)
God saw that the light was good, and God SEPARATED the light from the darkness. (5) God called the light day, and the darkness He called night.
+ 24-Hour Cycle= Star of David --> 'God SEPARATED the light from the darkness'
/ The Light, Day= Up (or Down) Triangle --> God called the light day, and the darkness He called night.
= The Darkness, Night= Down (or Up) Triangle --> 'and the darkness He called night.'
_________________________
(7)
God made the expanse, and SEPARATED the waters which were BELOW the expanse from the waters which were ABOVE the expanse, and it was so.+ The Waters= Star of David --> 'separated the waters'
= The Waters BELOW= Down Triangle --> 'the waters which were BELOW the expanse from'
/ The Waters ABOVE= Up Triangle --> 'the waters which were ABOVE the expanse'

_________________________
(9)
Then God said, 'Let the waters BELOW the Heavens be gathered into one place, and let the dry land appear', and it was so. (10) God called the dry land Earth, and the gathering of the waters He called Seas, and God saw that it was good.= The Seas= Down Triangle --> 'Let the waters BELOW the Heavens be gathered into one place'
/ The Earth= Up Triangle --> 'and let the dry land appear'
+ Planet Earth= Star of David --> 'and God saw that it was good.'
_________________________
(16)
God made the two great lights, the greater light to govern the day, and the lesser light to govern the night.+ 'Two great lights'= Star of David
/ Sun, the Greater Light= Up Triangle
= Moon, the Lesser Light= Down Triangle
_________________________
(20)
Then God said, 'Let the waters bring forth swarms of living creatures, and let birds fly ABOVE the earth in the open expanse of the Heavens.'
= The Fish= Down Triangle - 'the waters bring forth'
/ The Birds= Up Triangle - 'fly ABOVE the earth'
+ Wildlife= Star of David
_________________________
(27)
[b]God created man in His own image, in the image of God He created him, male and female He created them.[/b]
/ God= Up Triangle
= Image of God= Down Triangle
+ Creation of Man= Star of David --> 'He created him'
/ Male= Up (or Down) Triangle
= Female= Down (or Up) Triangle
+ Creation of Mankind= Star of David --> 'He created them'
_________________________
This simple, basic analysis provides one of best ways in explaining the ultimate reason why the Catholic Church, while acknowledging the hexagram as a legitimate family seal for the House of David (including Jesus Chris), has still tended, for literally hundreds of years, to refer to the Star of David as the Star of Creation. Considering the inherent common sense seen in the above interpretation of the Creation story in Genesis 1, it should be fairly easy to understand why.
Agree? Disagree? Hate, Love? Like, Dislike? All of the Above?
Relevant Quotes and ReferencesSix-pointed Star:
Route six corners correspond to the six days of creation. These are also the six attributes of God: love, power, wisdom, mercy, justice and majesty. It is also known as Star of David in Judaism. Six-pointed star - a Christian symbol- Christianity, Religious Symbols and their Meanings, Relijournal.com
Six Pointed Star:
Star of Creation, Star of David. Although ancient and symbolizing the six days of creation, best known in modern times as a symbol of Judaism.
- Christian Symbols, Symbols, Gocek.org