Gemstone Identification

[Nugget]

Hearing all this talk lately about Gemstones has got me highly interested in going out and finding some myself, the only problem is I wouldn't actually know what I'm looking for.

Has anyone got any pointers of what to look for, maybe explaining the different types that can found and the distinguishing features of each.

I look forward to your responses

 

[Gold miner]

My dad,
Who is back in the mother country now, was a lapidary/rock/gemstone man... but he did show me how to prospect for gold too back in the 80's!!He had the diamond saws, tumblers going for days, dob sticks and the lot!
What I didnt get, after seeing yellow stuff, was what the rocks, gemstones even looked like?!! I never have, and would probably be thowing diamonds out in my clean up sieve!! (coz I use angled riffles...sorry Wal!! )

Nugget,
Here's a site I used for SG numbers, I havent delved right into this place, but it does look interesting... might help ya?
http://www.gemselect.com/gem-info/specific-gravity.php

 

[joe]

some info on gems & locations : http://www.resources.nsw.gov.au/geological/industrial-mineral-opportunities

 

[Nugget]

Wow , that's a fantastic resource. I think I might have to stick that one up somewhere, thanks Joe.

 

[Nugget]

My dad,
Who is back in the mother country now, was a lapidary/rock/gemstone man... but he did show me how to prospect for gold too back in the 80's!!He had the diamond saws, tumblers going for days, dob sticks and the lot!
What I didnt get, after seeing yellow stuff, was what the rocks, gemstones even looked like?!! I never have, and would probably be thowing diamonds out in my clean up sieve!! (coz I use angled riffles...sorry Wal!! big_smile wink )

Nugget,
Here's a site I used for SG numbers, I haven't delved right into this place, but it does look interesting... might help ya?
http://www.gemselect.com/gem-info/specific-gravity.php

That's the sort of stuff I'm after, thanks GM.

Maybe you could start shipping your tailing's to me to go through

 

[joe]

Welcome Nugget, Geoscience have detailed maps and database of all gems just can't find the link


Think its this one http://www.ga.gov.au/cedda/maps/155

 

[WalnLiz]

some info on gems & locations : http://www.resources.nsw.gov.au/geological/industrial-mineral-opportunities

That's probably the pick of the sites out there Joe....Cheers Wal.

 

[Gold miner]

That's the sort of stuff I'm after, thanks GM.

Maybe you could start shipping your tailing's to me to go through

Can do mate...
I'll start shipping tomorrow..
You should see the first semi-road train by about 1030 hours...
dont forget.....

it's COD!! 8)

 

[Nugget]

Let me run it by the wife first, ah nut she said no :lol:

 

[Nugget]

Just a couple more questions guys . Are Gemstones usually heavier than normal rocks? and can they be found in say a sandy riverbed or does it need to be a rocky / creek environment?

I've got a river flowing just down the road from my place and the sand is mixed with pebbles, so I'm just wondering if Gemstones could be found there or if I'd just be wasting my time.

 

[axeman]

Gemstones are heavier than most stones, the 7 mile diggings in Queensland where I go chasing gold is granite country so the creeks are full of sand and not only is there gold in that but also small blue-green sapphires, industrial diamond and rubies ( red sapphire). Mick

 

[joe]

Depends on the location Nugget, clay, sandy soil, Rocks but important is to check the maps and existing occurrence.

Specific Gravity

Diamond has a Specific Gravity of 3.52. (Compared to Water at 1.00 - which actually means that 1 Fluid Ounce of water does exactly weight 1 Fluid Ounce!) Specific Gravity is the weight of an item against an equal volume of water. That's why when you drop a Diamond into a glass of water it goes straight to the bottom.

You would need to drop a Diamond into a much heavier liquid in order for it to float. (Like Pine Oil) The denser (heavier) a Gem is, the faster it will fall. You might be interested to know that a 1.00 Carat Diamond and a 1.00 Carat Ruby DO NOT weight the same. Ruby (4.0-4.1) is denser and will sink quicker than a Diamond does!



Specific Gravity of Gemstones

Achroite 3.06 Hornblende 3.28-3.41
Aegirine 3.55-3.6 Ivory 1.9
Agate 2.65 Jade 3.24
Albite 2.6-2.63 Jadeite 3.24
Almandine 4.1-4.3 Jet 1.33
Almandite Garnet 4.52 Kyanite 3.67
Andradite Garnet 3.86 Kunzite 3.18
Amber 1.08 Labradorite 2.69-2.72
Amethyst 2.65 Lapis Lazuli 2.8
Aquamarine 2.69 Lazurite 2.4-2.5
Augite 3.23-3.52 Magnetite 5.2
Azurite 3.77-3.78 Malachite 4
Barite 4.5 Marcasite 4.92
Benitoite 3.67 Mercury 13.6-14.4
Beryl 2.6-2.9 Milky Quartz 2.65
Biotite 2.7-3.4 Moonstone 2.57
Bloodstone 2.65 Morganite 2.6-2.9
Brazilianite 2.94 Muscovite 2.77-2.88
Calcite 2.71 Nephrite 2.96
Carnelian 2.65 Olivine 3.27-4.32
Cassiterite 7 Opal 1.9-2.3
Chalcedony 2.65 Orthoclase 2.56
Chalcopyrite 2.65 Padparadscha 4
Chatoyant Quartz 2.65 Pearl 2.71
Chromdravite 3.0-3.2 Peridot 3.34
Chrysoberyl 3.65-3.8 Platinum 21.4
Chrysoprase 2.65 Pyrite 5
Cinnabar 8.0-8.2 Pyrope 3.5-3.8
Citrine 2.65 Quartz 2.65
Copper 8.9 Riebeckite 3.32-3.38
Coral 2.68 Rock Crystal 2.65
Corundum 4.0-4.1 Rosy Quartz 2.65
Demantoid 3.52 Rubellite 3.06
Diamond 3.52 Ruby 4.0-4.1
Diopside 3.22-3.28 Sapphire 4.0-4.1
Dravite 3.06 Sardonyx 2.65
Emerald 2.71 Schorl 3.0-3.2
Enstatite 3.2-3.4 Shell 1.3
Fire Agate 2.65 Silver 10.5
Fluorite 3.18 Spessartine 4.16
Forsterite 3.27-4.32 Sphalerite 3.9-4.1
Galena 7.58 Spinel 3.6
Garnet 4.1 Spodumene 3.18
Glaucophane 3.08-3.15 Sulfur 2.0-2.1
Gold 19.3 Sylvite 1.99
Graphite 2.1-2.3 Tanzanite 3.36
Grossular 3.49 Topaz 3.54
Gypsum 2.32 Tourmaline 3-3.2
Halite 2.1-2.2 Tremolite 2.9-3.2
Hauyne 2.44 Turquoise 2.6-2.8
Heliodor 2.6-2.9 Uvarovite 3.77
Hematite 5.26 Watermelon Tourmaline 3.06
Hessonite 3.6 Zircon 4.0-4.8
Hiddenite 3.18

 

[Syndyne]

Hi all,

^That's a great SG table Joe. Cheers for posting that!

Nugget, if you can also get out to a garage sale or two, even a secondhand book store, they always have a good chance of having a decent gold/gem book or two for a couple of bucks.

It's not only prospecting equipment taking up all my spare room these days, it's also a large number of old gold, geology and rock & mineral books. These days as the older, more knowledgeable prospector numbers dwindle it's becoming more and more important to gather up and hold onto the good info about some out of the way areas that might soon be lost forever.

All the best,
Shauno.

 

[Nugget]

Thanks guys, that's some very helpful information. I wasn't aware that there were so many different types, I'll definitely research my area to see whats about.

 

[Colin&Lee]

Zircon or am I being optimistic Ruby?

Another quick one the green crystals you find at GG are they green Garnet or Tourmaline?

Cheers

C&L

 

[WalnLiz]

The dark one with the zircons will prob be a garnet though some of the zircons do get quite dark,.... unfortunately it's definitely not a ruby. The green ones are from the tourmaline family and are still a semi precious gem that can cut a nice stone if light enough....Cheers Wal.

 

[Hunting the yellow]

yeah ill have to agree the dark one is a garnet but you have really nice gems there

 

[R_G_Bargy]

I'd be thinking the Red one is a zircon, they cut to be a stunning stone. The way to tell zircon from garnet is by using 2 polarized lenses. Zircons are doubly refractive and garnets are singly refractive. If anyone is interested and has the polarized lenses I can tell you how to make a simple polariscope. If my memory of GG is right, the yellow/green colloured material is olivine. It's lighter then the concentrates in the bottom of the pan and washes around with the sands more so. Remember to always take home anything that looks interesting that you are unsure of, it could be valuable!

 

[Colin&Lee]

Remember to always take home anything that looks interesting that you are unsure of, it could be valuable!

Don't tell Lee that I have enough piles of interesting rocks I have to try and get rid of as it is

Cheers


C&L

 

[Jed]

Hi R_G_Bargy - being a gadget guy I would be very interested in how to make a simple polariscope
cheers
Jed