Opal and Mars?

is there opal on mars?

Photos provided courtesy of the NASA website

For some time there has been a discussion in some geological and other science places that there has been a discovery of opal on Mars. The discussion began? in about 2014 and was reported by NASA. The web page for NASA has a reference to opal on Mars, labelled as : “A Gem of a Find”. you can find a link to the reference in the paragraph on literature below. This is discussion is perhaps an old story, and we at the Academy have not seen any more recent discussion regarding opal on Mars (if any readers have more information send us a comment)! Still the NASA website will have access to the relevant information. Further to the discussion, at the time that NASA elucidated the possibility of opal on MARS, it naturally spawned a number of geological papers that suggest some similarities about the geological environments on MARS and the potential for examining if there is a relationship to terrestrial geological environments with the environments on the surface of MARS.

If there is “opal” on Mars, then it is not to far to go to envisage that this relationship of formation regarding “opal” may highlight some interesting facts about processes that may be appropriate or in correlation for both planets.

There are two geological papers related to this discussion, again both of them are published around the time of 2014-2015, and links to these papers are provided in the literature paragraph below. Further to these two papers is a scientific Thesis authored by Boris Chauvire submitted in 2015,16. and links to a couple of pages are also given in the literature below. These pages and references are geological and scientific literature and as such show the complex nature of the discussion. It should also be noted that at least for the two geological papers that the references to MARS are perhaps a sidelight to the topic of opal formation being discussed.

The interesting part from the point of view of MARS explorations and the scientists examining the data is If there is opal on MARS, then there is evidence that there is or has been water on MARS. This becomes important for the further exploration or even the ability for humans to visit the red planet.

You may ask why, and the answer lies in the chemical constituents of OPAL. Opal is chemically SiO2.nH20, or expressed in a different way, opal has water in it! And if there is water in the opal, then there is or has been water on MARS.

FROM a gemmological point of view: what type of opal?

Here is a very interesting question! Before we begin, lets consider what “opal” is. Opal is a term which is given to what may be called a “family of polymorphs”. Opal is now being considered as a “Mineraloid” as distinct from just being a “Mineral” ( we will consider this in discussion on the Opal Academy at a later date). Considering this interesting aspect of “opal”, the material (opal) comes in many different types, varieties, and forms. As are recommendation readers would be advised review the discussion about these different forms in our opal nomenclature post. You can read about the mineralogical nomenclature here:

For those non gemmologists, and non scientists the differences come down too hw the opal “components” are arranged. That is how do the Silicon atoms (Si) , oxygen atoms (O) and water interact together in different ways.

Many readers of opal information on the International Opal Academy website are more interested in the consideration of and appreciation of opal as a phenomenal gemstone. This is often also true of other authors in the media wanting to enhance the attention to an article written about opal. So in this instance the obvious question becomes does the opal on MARS have Play-of-colour(POC)? Is it a gemstone?

The question to examine more closely then is: what type of opal is the opal on MARS? And then the discussion will likely come back to a discussion between Mineralogy and Gemmology. Is the opal that has been discovered on MARS, gem opal or common opal?

This can lead to a poorly defined categorisation of opal, or a misunderstanding, between “Opal” as a mineralogical term, and “Opal” as a gemmological term.

There can be confusion here, from a mineralogical point of view, opal can be defined by X-Ray Diffraction, Infra-red Spectroscopy and a number of other scientific analyses. (we are working on providing this information on the Academy website). From a Gemmological point of view we are saying “does it have a Play of Colour”? Or another way of saying this is it Precious Opal, which might also be translated to does the opal have a “Sphere structure” like precious opal? Or not.

Most scientific literature as published today does not distinguish between “Opal” polymorphs or varieties in this way, that is there is often not consideration for the gemmological viewpoint. As a consequence, mineralogists and geologists perhaps, are only concerned with the silica structure, or the structure of the atoms of silica and oxygen, and the incorporation of water, this may be their predominate point of view, perhaps they often do not ask, is it “Sphere type opal”? Does the structure show the regular array of silca spheres seen in Precious Opal? Opal and silica mineralogy, is complex and we at the International Opal Academy believe that there is a need (perhaps a desperate need) to reconcile mineralogy with gemmology!

We would then advocate for a greater emphasis on the type and variety of the opal being discussed in any scientifically published paper. Lets not just say that is “opal” lets state whet “type” of opal it is. There are very important implications and reasons for going down this track.

is there opal with a play of colour on mars?

Here is an interesting question, is there Precious Opal on MARS? The answer is we do not know. However the NASA post states “The opal appears to be light toned and appear (as) cream coloured in the photo” in the picture is provided by NASA. If you read the NASA post, you will realise by looking at the photograph provided that the picture to which the reference talks, is from a MARS orbiter rather than a rover on the ground (surface) of MARS. The post also states that the Martian rocks are “a mineral similar to opal. Mineralogy, and remote sensing cannot show us this information at the present time. The experiments cannot reveal to us if there is a sphere structure to the opal. They can only give us a partial examination that there is silica and water in a mineraloid. As we refine the analysis of opal mineralogy, then we may be able to make this distinction. Further exploration and analysis may well discover more information or a technique that allows a distinction to be made that determines …is it sphere type opal? or even is it sphere type opal that has been changed.

literature

There are a number of pieces of literature on this subject. This is what we have at the Academy.

https://www.nasa.gov/multimedia/imagegallery/image_feature_1251.html

Opalization of the Great Artesian Basin (central Australia): an Australian story with a Martian Twist. PF Rey, (20140 Australian Journal of Earth Sciences(AJES), V60, p291-314. You can source the whole article here: https://doi.org/10.1080/08120099.2013.784219

Or you can read the relevant paragraph, which is an extract from the article by Patrice relating Australian opal geology and the possible relationship with Mars Exploration here:

Discussion and reply: AJES,V60, p831-833, (2014), Dickson, BL https://doi.org/10.1080/08120099.2013.870093

You can read the relevant passage from Bruce Dickson’s reply to Patrice here:

Genesis of Supergene Silica on Earth and implication on Mars, Thesis, University of Nantes, In French. (2015)

The first extract from Boris’ Thesis here is from Part 4 of Chapter 1 and is an introduction to the detection of silica on MARS: read it here:

This second extract from Boris’ thesis is from Part 2 of chapter 5, it is a more complex discussion regarding the methods of detection of silica on MARS: read it here:

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