Unknown Green Crystal/rocks need identifying

Hi all

Is this Chrysoprase? Wrong crystal system from what I can read on it.
Found in Central Qld area on private property. Alway opaque green, very few show the crystal structure. Comes in different shades of white/green to dark green patches in crevices. Seems to be associated with a white to clear rhombus shaped crystal.
No known copper in the area.



?

Sure is an interesting looking material! Maybe post this in the "Mineral identification questions answered" thread where Goldirocks will see it.

I've never viewed chrysophrase as it's coming out of the ground but none of the big chunks I've seen -up to a couple of feet across - really resemble that.

Do you have any pics of rhombus-shaped crystals associated with it?

Cheers

As requested

Some variety of calcite maybe? Could both specimens be the same mineral, in in crystal form and one in more massive form? Definately very interesting and one for Goldirocks.

How hard is it, roughly speaking?

If calcite maybe copper carbonate / malachite may be the greeny blue. Gday Lefty!

Gday AR! I've never come across anything that looks quite like it while out fossicking.

If it is a calcite, a nice, perfectly clear crystal should be strongly doubly refractive (and quite soft). I think?

If it were hard enough, some of those colourful patches might make nice cabs.

Nickel is the element responsible for the color in chrysoprase.

Lefty said:

I've never viewed chrysophrase as it's coming out of the ground but none of the big chunks I've seen -up to a couple of feet across - really resemble that.

Click to expand...

A bit off topic but this is chrysoprase in the host rock at the old Wingellina chrysoprase mine WA. Slap bang in the middle of one of the worlds largest undevolped Nickel reserves. Plans to build a processing plant near the mine the size of the center of Perth WA.

"Mineral identification questions answered" is a better place for these (so I don't miss). Looks suspiciously like multiple minerals to me (perhaps even three). Crystals look like calcite so should be hardness 3 (can scratch with gold coin but not with fingernail). I suspect that the green mineral is more likely a copper mineral than chrysoprase (what is hardness)? Chrysocolla perhaps? It never forms crystals, often botryoidal, can have a conchoidal to uneven fracture, probably slightly harder than the calcite (sometimes nearly as hard as chalcedony), varies from blue to green.

https://en.wikipedia.org/wiki/Chrysocolla

However there are many green copper minerals. Some are carbonates, others phosphates. For example, poor quality turquoise can be that colour, varying green to good-quality blue - commonly occurs with copper prospects, black slates, often phosphatic rocks (eg King River Valley, South Coast NSW)

Mr Magoo said:

Nickel is the element responsible for the color in chrysoprase.

Lefty said:

I've never viewed chrysophrase as it's coming out of the ground but none of the big chunks I've seen -up to a couple of feet across - really resemble that.

Click to expand...

A bit off topic but this is chrysoprase in the host rock at the old Wingellina chrysoprase mine WA. Slap bang in the middle of one of the worlds largest undevolped Nickel reserves. Plans to build a processing plant near the mine the size of the center of Perth WA.

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461650_host_rock.jpg

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461680_mine.jpg

Click to expand...

Often the associated rock is a clue (eg chrysoprase is usually associated with serpentinite or a fairly mafic rock).
I remember the early days at Wingellina during the nickel boom. Some Indigenous guys came into camp excited and said there were "Kadaitcha Man" footprints on the airstrip. The blokes rushed out for a look - didn't find any but when they returned the grog had disappeared....

Although Kadaitcha was supposedly not practiced after the 1930s, a pair of boots (emu feathers held together with blood) were found by a mate under a rock ledge in perfect condition.

Getting way off track...

Mr Magoo said:

Nickel is the element responsible for the color in chrysoprase.

Lefty said:

I've never viewed chrysophrase as it's coming out of the ground but none of the big chunks I've seen -up to a couple of feet across - really resemble that.

Click to expand...

A bit off topic but this is chrysoprase in the host rock at the old Wingellina chrysoprase mine WA. Slap bang in the middle of one of the worlds largest undevolped Nickel reserves. Plans to build a processing plant near the mine the size of the center of Perth WA.

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461650_host_rock.jpg

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461680_mine.jpg

Click to expand...

Those chunks look very similar to the big chunks I've seen in collections. Similar looking host rock and all.

Here's a 16.4 tonne chunk of Marlborough material.

There's a nickel mine in the area from memory, been past plenty of times but you can't go in there.

Although Kadaitcha was supposedly not practiced after the 1930s, a pair of boots (emu feathers held together with blood) were found by a mate under a rock ledge in perfect condition.

Click to expand...

Designed to erase their tracks as they walked I believe?

Lefty said:

Although Kadaitcha was supposedly not practiced after the 1930s, a pair of boots (emu feathers held together with blood) were found by a mate under a rock ledge in perfect condition.

Click to expand...

Designed to erase their tracks as they walked I believe?

Click to expand...

Yep, so he walks around you at night and points the bone, then heads off - in the morning you can't tell which were the tracks coming and which going as they are simply oval and symmetrical.

I've seen it suggested that one reason you died was that - since you were doomed - no food or anything else would be shared with you. Who knows if true?

And yes, I can't exclude the possibility of chrysoprase - is it associated with a greasy green rock easily dug with your knife, with lots of chalcedony boondies scattered around? Copper minerals will give a green to bluish green flame test, chrysoprase (nickel) will give a silver-white to colourless flame (eg a candle flame will change from yellow to white).

If those crystals are calcite and Brumble-Gum has a transparent one, he should be able to achieve this effect looking through it?

Lefty said:

Mr Magoo said:

Nickel is the element responsible for the color in chrysoprase.

Lefty said:

I've never viewed chrysophrase as it's coming out of the ground but none of the big chunks I've seen -up to a couple of feet across - really resemble that.

Click to expand...

A bit off topic but this is chrysoprase in the host rock at the old Wingellina chrysoprase mine WA. Slap bang in the middle of one of the worlds largest undevolped Nickel reserves. Plans to build a processing plant near the mine the size of the center of Perth WA.

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461650_host_rock.jpg

https://www.prospectingaustralia.com/forum/img/member-images/3008/1529461680_mine.jpg

Click to expand...

Those chunks look very similar to the big chunks I've seen in collections. Similar looking host rock and all.

Here's a 16.4 tonne chunk of Marlborough material.

There's a nickel mine in the area from memory, been past plenty of times but you can't go in there.

Click to expand...

I know where this area is. I am a few hours North of this location.

Lefty said:

If those crystals are calcite and Brumble-Gum has a transparent one, he should be able to achieve this effect looking through it?

Click to expand...

I have tried this test and it appears that this is double refracted. It is a little hard with the green "knobby" bit sticking out and it is not clear as the ones on the website. But you can see that words are blurred under it. I need to have this cut with a lap saw to remove the knobby bit.
As for the rock hardness, it is not soft at all. It is quite hard, I actually had to use a bit of granite to remove the calcite (or whatever) from its origin.
Both green and white/clear are about as hard as quartz crystals.

Are you quite sure that you do not have three minerals, quartz (or chalcedony), calcite and the green one? You need to test each one with the sharp point of a small steel pocketknife. Calcite is only hardness 3 (scratch with a coin) and even the other carbonate minerals (the rhomb you have indicates a carbonate mineral) are always softer than steel. I wondered if the main block was quartz or chalcedony (white) and the crystalline stuff calcite (white) plus a green mineral (both chrysoprase and chrysocolla can be hard but are often a bit softer than quartz).

I say use the tip of the knife, and test a few spots - sometimes two intergrown minerals of the same colour can look like one mineral.

Powder for flame tests can be got from what you scratch out, or I sometimes use a dentist drill.

Looks like this.

Nice work there Potsey... :Y: ] ]

LW....

I can definitely confirm that the green is not chrysoprase. I have some that I obtained from an old Chrysoprase mine and it looks nothing like it.

The nodular stuff in the second photo from the top looks a little bit like prehnite to me.