
Hexagrams appear on Bulgarian postage stamps issued in 1993. Based on the context it seems that they represent the planets or the stars.
This blog (by Zeev Barkan) is dedicated to the Star of David, its history, its various meanings and usages in different cultures. It includes thousands of pictures of Star of David, six-pointed stars, hexagrams, Solomon's Seals, Magen Davids and yellow badges,and served as a resource for three books and four art exhibitions.

Hexagrams appear on Bulgarian postage stamps issued in 1993. Based on the context it seems that they represent the planets or the stars.
I asked Israeli astrology expert Khoschen-Klein Monius about appearances of the Star of David symbol in astrology and he answered that astrologers speak about Double Trines (aspects) that form this symbol on the astrological map. (Trines= equilateral triangles).
Then I Googled “Double Trines” and found out that in November 8-9, 2003, there was a lunar eclipse along with a configuration of 6 planets creating a Star of David formed by the two Grand Trines (Double Trines).
It sounds quite interesting to find out if that date, November 8-9, 2003, changed someone’s personal course of life, or if it changed the global course of life – what do you think?

Picture of Mary with the twelve zodiac signs (hexagrams) is courtesy of “tpol33” from Flickr who shot it at the Cathedral of Cologne, Germany. The Statue is called Virgo Immaculata and it was made in 1749. This is the first instance of hexagrams representing zodiac signs that I stumbled upon.
It seems like an illustration of Revelation Chapter 12:
1 A great sign appeared in the sky, a woman
2 clothed with the sun, with the moon under her feet, and on her head a crown of twelve stars.

What is the meaning of these Hexagrams in the Cathedral of Cologne, Germany?
Picture is courtesy of Marco Braun from Flickr.
Magen David appears on top of this 1928 Maccabiah certificate, which shows that Eliyahu Catz won the first place.
Copyright: Rony Dror 2008 Maccabi Archive, Kfar Hamaccabiah
Thanks to Dobush from Kfar Aza for referring me to this unique document.

Hexagrams appear on the top corners of this illustration, which is titled:
"The Temple of the Rosy Cross". From: Teophilus Schweighardt Constantiens, 1618
Copied from Wikimedia entery Image:Templeofrosycross.png uploaded by Campani

The six glyphs of the planets surround the Sun; each glyph occupies another triangle of a hexagram. Picture is from Opus Medico-Chymicum, an alchemy book by Johann Daniel Mylius published in 1618. The usage of the six-pointed star to represent the planets is a new discovery for me, and I’ll appreciate it if readers could refer me to articles about this subject, or to other pictures that show this kind of usage.
I reckon that the planets in this illustration represent the days of the week, while the zodiac signs represent the months:
Copyright: “abramelin” from Flickr 2008