| Could you believe that until 1960 or so no one | | | | the silica gel. Colored elements that seeped |
| actually knew how opal got its color? Firstly, let's | | | | through the rock, got caught up in the opal gel |
| answer the question what color are they? The | | | | and as it hardened became responsible for its |
| answer is simple: every color you could think of. | | | | color. This is just not so. |
| Opals cover the full spectrum of color. | | | | Opal color comes from its unusual structure and |
| Then there is just about every mix of colors that | | | | how white light is affected by it to break into its |
| you might imagine. I don't think I could name a | | | | spectral colors. In the 1960s Australian scientists, |
| color that I haven't seen in opal. | | | | using technology not previously available, |
| It is easy to understand why some gems get | | | | discovered that opal is composed of |
| their color. Sometimes it is a make up of the | | | | submicroscopic spheres which are responsible for |
| crystalline structure, or it might be and mostly is | | | | the magic play of color. Because of this |
| because there is some element such as iron, | | | | arrangement of spheres opal is the only |
| copper, aluminum or something else which is | | | | gemstone with the natural ability to diffract light. |
| basically an impurity which gives the gemstone its | | | | Naturally, the base color whether it is white, black |
| color. Why are rubies red? Why are emeralds | | | | or non existent will play a role in what an opal |
| green? Well, as one example, it is chromium, | | | | looks like and the colors that we see. Even when |
| vanadium or iron elements in the stone which | | | | a crystal opal is set on a gold or silver plate in a |
| make that lovely green colour. Why are diamonds | | | | pendant it will show some of the metal's color so |
| clear? | | | | there are a lot of factors which promote |
| Most miners used to think and many still think | | | | different colors after the stone has been taken |
| that the colour of opal comes from impurities in | | | | out of the ground. |