FMF - Friends of Minerals Forum, discussion and message board

[zanthal]

Pics here:
https://picasaweb.google.com/innerspacewalk/RockAndMineralCollection#
(link normalized by FMF)

[Debbie Woolf]

I took a look at the link, nice set you have there, only I did say it looks similar to Ocean Jasper its not confirmed 100% ... I also see you have Blue Lace Agate, as pointed out to me recently its Chalcedony, Blue Lace Agate is a marketing term although heavily used even by professionals !

[John S. White]

I have three observations/questions for you Zanthal.

1. I am quite sure that the jasper, if it is jasper, is not ocean jasper
2. Why do you call the one selenite instead of its proper mineral name gypsum?
3. Have you tested the "alabaster calcite" to see if it is indeed calcite and not gypsum?

[zanthal]

> I took a look at the link, nice set you have there, only I did say it looks similar to Ocean > Jasper its not confirmed 100% ... I also see you have Blue Lace Agate, as pointed out to > me recently its Chalcedony, Blue Lace Agate is a marketing term although heavily used > even by professionals !

Thanks for the info. I'm beginning to see a pattern here, when the names are prettier sounding than the stones themselves, it's probably a marketing ploy.

> 1. I am quite sure that the jasper, if it is jasper, is not ocean jasper
> 2. Why do you call the one selenite instead of its proper mineral name gypsum?
> 3. Have you tested the "alabaster calcite" to see if it is indeed calcite and not gypsum?

1. It was the best answer I could come up with, so rather than leave it un-named, I took Debbie's suggestion.

2. I hadn't gotten around to changing the name after your post saying it was definitely not selenite. (I have done so now, thanks)

3. I haven't done any tests beyond scratching a small part of the surface (using tool pictured below). It scratched fairly easily, the scratchings being small chips.

[zanthal]

John,

Scratch test of the Gypsum piece helped. The egg in question, especially after comparison to photos of Alabaster Calcite makes me pretty confident with the ID.

The reddish-brown area on the bottom of the egg is puzzling. I thought at first it's iron-oxide, but it seems too orange to be so. In fact a lot of the orange coloring reminds me of Carnelian. I'm probably wrong though.

Do you have an opinion about it?

[John S. White]

You have used the wrong took for the scratch test. If the stone is gypsum, you can scratch it with your fingernail. If calcite a needle point will scratch it easily, usually leaving a powder which will dissolve in vinegar.

[zanthal]

> You have used the wrong took for the scratch test. If the stone is gypsum, you can > scratch it with your fingernail. If calcite a needle point will scratch it easily, usually leaving > a powder which will dissolve in vinegar.


I'm not surprised. Need to get some more facts straight. I'm armed with several books from my local library now, ought to help.

We'll see about the vinegar test.