Help with white/yellow Stone with rust colored spots

[Phate008 3]

Is this a mineral? I found this on a beach while searching with my metal detector. It's not magnetic, but I found it in a hole in the sand I was digging. It had barnacles on it so I know it was in the ocean for a while. I had trouble searching around for it, but it looked like a picture of a website claiming it was amethyst. This didn't sound right to me I always thought amethyst was purple. Maybe some kind of quartz?

 

I was also thinking of polishing this and making it shiny and possibly making a jewelry pendent out of it. What kind of tools/equipment would I need to get this filed down to a nice size and polished and shiny? 

 

Thanks for any help

[Diggingd 36]

It definetly looks like quartz, amethyst is typically purple, but I have heard of a few pink ones being found recently (the purple is from irradiation and impurities from iron). It could be that it is iron oxidation making it have the red color, but that would be an external impurity rather than an internal one. I'm sure some of the guys that know a lot more than me can give you a better answer.

[fuss 37]

Could also be a feldspar or calcite based on the appearance of it, try to scratch it with a knife , feldspar and quartz wont scratch calcite will. The red portions could be iron oxide stains like Diggingd said, or another mineral tough to say based just on these photos. Not Amethyst though.

[23XLive 17]

In the second picture, the white looks like calcite to me.

[Diggingd 36]

Could do an acid test to, try dropping a couple of drops of vinegar on it and see if it fizzes, if so calcite. (Wont harm it at all) 

 

[Phate008 3]

Ok thanks. I will try the acid and get back. Thanks for the comments

[Phate008 3]

So I poured a generous amount of white vinegar on it and there was no reaction, it just made it wet. Also tried to scratch it with a sharp knife but it wasn't making any marks.

[chrisski 789]

To me it looks like a fairly typical, although not typical to your area, quartz rock with some other mineral in it.  My guess the story about how it got there could be interesting.  Could have been part of a bigger ballast rock that broke off that came from a 17th century sailing ship, could have been carried by an Indian on a trade route and dropped, could have washed naturally out a river many miles away and got tossed back on a storm, could have been a landscaping rock someone brought to the beach to skip on the water.

In the middle of the desert central AZ, I found an old clam shell in hard packed gravels that I thought was a fossil when I found it, but after finding a second, I think it may have been along one of the Apache trail routes.

Quarts is a really common mineral.  I lived in North West Florida on the Panhandle, and the beach sands are almost pure white and supposed to be made of a lot of quarts sands.

Edited August 17, 2019 by chrisski