What is Luster Called in Gemstones?

Luster is referred to the light reflected from the surface of gems. In some gemstones, there is internal light reflections also such as facet stones with transparency. However internal reflection of light is not called luster. It is called brilliance. Luster is the way a mineral either shines or does not shine. Gems and minerals can have metallic and non metallic luster.

Various terminology are used for defining luster for a gemstones. Such as Adamant, Vitreous, Silky, Greasy etc. Normally luster can be defined in two categories:-

  1. Metallic (such as pyrite , hematite)
  2. Non Metallic (all gemstones)

One will get in gemstones most non metallic gemstones. Following are described brief description of each luster type:;-

  1. Adamantine
  2. Sub Adamantine
  3. Vitreous 
  4. Sub Vitreous 
  5. Greasy
  6. Silky
  7. Pearly
  8. Resinous
  9. Waxy
  10. Dull
Non-Metallic Luster Appearance
Adamantine Sparkly
Earthy Dull, clay-like
Pearly Pearl-like
Resinous Like resins, such as tree sap
Silky Soft-looking with long fibers
Vitreous Glassy

Adamantine

Adamantine is highest form of luster just like mirror. Its best example is Diamond.

Sub-Adamantine

Some gemstones has luster like diamond but they are not fully adamantine. However they are closed to adamatine. They somes in sub-adamantine category. Their examples are Cubic Zircon.

Vitreous

Some gemstones have glassy like shining on surface such as tourmaline, Quartz, topaz.  The majority of gems show a vitreous luster. Examples are beryl, quartz, topaz, ruby, emerald and others with refractive indices between 1.50 and 1.70.

Sub-Vitreous

In sub vitreous, the gemstones are included which have low reflection of light on surface such as flourite.

Greasy

Gems with greasy surface will have oil like or fat like. The example is serpentine. Another example is garnet or peridot. These luster are characteristic of those polished surfaces that are not perfectly flat but that approach flatness.

Silky

The gemstones with silky luster will be based on having some fibrous material such as Gypsum and Malachite. Another example is Ulexite or moonstone. They look like having texture of fabric. Polished tiger’s eye shows a vitreous luster on its surface, overlaying a fibrous body.

Pearly

Some gemstones have orient luster which is called Pearly. They show an iridescent play of colors on their surfaces.

Resinous

Amber are consisted of preserved prehistoric plant resign. This gemstone have resinous luster example in best. Sphalerite has also resinous luster. The gem materials that are soft and have low refractive indices, like Amber and Opal.

 

Waxy

Some gemstones looks like having kind of a wax on surface. Best example is turquoise and Opals

Dull

As this is shown by name that gemstone with having dull luster will be reflect very very low light. Dull will have fine grain like surface.

Metallic

Some gemstones or minerals have metallic matters in them. Such as Pyrite and Hematite. Though

they are not used as gemstones in general however in some cases, they are.

How to Photograph Gemstones and Minerals?

Photography of gemstones is an art . They have highly reflective surfaces that can reflect light back into the camera lens overexposing the facet and frequently burn into adjacent facets as well. Gemstones also have internal brilliance that act in much the same way as the surface reflections.  They always need specific light and background to make clear the quality of gemstones in such a way that a photo of gemstone can speak all its characteristics. Though it is not difficult to photograph the gemstone. The only method needed is how to deal with gemstones.

List of a Few Equipment you need before photographing a gem?

  • Camera or Mobile Phone – Camera should be capable of shooting images of 16 mega pixels or above.- In Case of Mobile, samsung zoom is good. iphone takes original colour photos. Main thing is needed to focus the object and light.
  • Macro Lens – 60-80 mm macro lens capable of 1:1 magnification enables you to focus on the object from 5 inches distance or more.
  • Tripod – Tripod will help you in movement. It will finish the movement of camera while taking photos.
  • Lighting and setting (A Light box will help )
  • wireless shutter

Camera Macro Lens

Cheap and Easy way to make Light Box

Setting before Beginning

  1. Wash your gemstones so that macro setting of camera may not capture the dust and scratches
  2. Stabilize the Tripod. If it is not available, set your camera in fixed position or set mobile phone
  3. For Mobile devices, use wireless shutter. Touching your mobile screen will not be able to focus on the object.
  4. Clip-on macro lenses are available for smartphones from a variety of manufacturers for Apple and Android devices. ōlloclip macro is a good one and is portable.

Choose your Background Setting

While coshing background, it is very important to crate a dramatic set up. If you want accuracy or focus on the gemstone or mineral, one will chose neutral coloured background. Background depends on gemstone colour or gemstone type. Some mineral specimens loks more clear in natural background. Some faceted stone looks more clear in plain background.  There can be two types of background settings:;-

  1. You can make a light tent out of almost anything that’s translucent.
  2. White Background 
  3. Black Ground
  4. Mix background 

You need to figure out which background is reflecting on stone much better than the other. Quartz will need black back ground. Blue will need white background. Aquamarine with more blue will need both types.

Lightning

Lightning plays important roles in the photography. In gems world, lightning has key role. Lighting determines the appearance of the gem–how the facets reflect the light–and the color of the gem, via the spectrum of the lighting.  Gems are of different colors which are reflected in different light setup. Some of the them are described here below:-

  1. White LED Day Light 
  2. Reflected Light 
  3. Yellow LED Light 
  4. Sunlight before afternoon 
  5. Sunlight 2 hours before sun set 
  6. Dont use Flash in most of the time especially when you are working with close up shots. 
  7. Adjust the white balance on your camera

Sometime, you have to take photos n white LED light and sometimes yellow light. Some times, you have to mix both. Sunlight in the morning till 1 hour before afternoon is the best time for taking photos. But its not necessary you get the best background always if one is living in cities metropolitan life. So you have to set up artificial day light.

Here are some tips over lightning:-

  • Try to use single colour light
  • Throw direct light on some gemstones like cut or those which has some affects like cat’s eye.

  • Some gems will demand indirect light. For this, light with white parachute can help. Throw light from outside parachute to inside which will throw the reflections.

  • A mix of direct and indirect or diffused lightning can make the picture beautiful by adding shining or dispersion to a transparent gem.

  • A high polished gems can be problematic with some direct lights. So that case, indirect lightning will help.
  • You can take picture in sunny day in a shadow because shadow will be reflecting the light.
  • Faceted stone would not work under sunny day as sunlight will sparkle the facet and you would not be able to catch the individual facet.

Day Light Bulb

Positioning of the gemstones

Positioning of the gemstone plays a vital role int he picture. The angle of gemstones matters a lot in final photo.

  1. If the stone is rough faceted grade like tourmaline to make clear xis view clear, its top surface has to put before light so light reflection can be seen easily.
  2. For stones like which have stars, they should be positioned in such way that through light, the star should appear in center.

 

Adjusting Focus

Focus is the main factor which plays a role in taking fine picture. In fact, this is the weak point. You have to select the point on stone to focus your camera. People need to know the maximum focal length of their lens. Pictures end up out of focus because they’ve gotten closer than the limit of the lens. They need to know where things go out of focus. If it’s too close, they need to use a different camera or a zoom mechanism.

 

If one will loss the focus area of mineral specimen, you are going to be out of giving unique detail of the specimen. It is better to take test photos for reviews.

Distance

  • One needs to be able to focus on an object from about 6 mm in diameter on up.
  • Optically the rule is that the longer the focal length of the lens the narrower the angle of view; hence the greater the working distance.
  • 105 mm lens is the best one as it will give opportunity to light to throw all around. Minimum length or distance would not allow throw of light. However with adjustment, 60 mm to onward works well.

Composition and Editing of Photo

After taking photos, editing is the final stage. It needs following activities :-

  1. Transfer the image in computer
  2. Cropping
  3. Colour balance
  4. Adobe Photoshop
  5. Different Aps in mobiles

Make sure that picture quality may not loss during editing.

Here is a tip to get macro photos from phone

Research Paper on the Enantiornithine (Baby Bird caught 99 Milliion years ago in Burmese amber)

A baby bird from Dianosour time was caught in amber dated approximately back to 99 million years ago. The amber is 99 million years old according to scientists writing in the journal Gondwana Research.

Here are pictures of bird from different angles.

Sizes and Measurements:-

Size:  86 mm x 30 mm x 57 mm,

weighs: 78.16 g,

The bird belongs to the group of birds called Enantiornithes which extincted along with other spices of the time i.e. dinosaurs at the end of Cretaceous Period about 65 million years ago. The discovery is very interesting as it is providing wonderful information about the ancient birds in understanding that how they were different than modern birds. This discovery implements the most complete fossil which has been discovered till now in Burmese amber. It is minded in the Hukawng Valley in Northern Myanmar.

The new specimen, HPG-15-1, comes from the Angbamo site, Tanai Township (Myitkyina District, Kachin Province) of northern Myanmar. There has been publication of complete research paper on this fossil

Research Paper on This Amber 

The original specimen is housed and displayed in the Hupoge Amber Museum (=HPG), Tengchong City Amber Association, China; the 3D reconstruction is available to researchers through the Dexu Institute of Palaeontology (=DIP), China.
The two pieces of amber forming HPG-15-1 were examined with a Leica MZ 12.5 dissecting microscope with a drawing tube attachment. Photographs were taken using a Canon digital camera (5D Mark III, MP-E 65MM F/2.8 1-5X) fitted to a macro rail (Cognisys), and were processed using Helicon Focus 5.1 and Adobe Photoshop CS5 software to increase depth of field in the images. These images were supplemented with photos taken under long wavelength UV light, mapping resin flows.

HPG-15-1 was scanned with a MicroXCT 400 (Carl Zeiss X-ray Microscopy, Inc., Pleasanton, USA) at the Institute of Zoology, Chinese Academy of Sciences, Beijing. A single scan of the entire piece was not possible due to its large size. The different parts of the bird were scanned separately. The head, neck, wing, and hind limbs, were scanned with a beam strength of 60 KV, and an absorption contrast and a spatial resolution of 18.3298 μm, 18.3298 μm, 3.7795 μm, and 25.5308 μm, respectively.

 

 Results

The following bird parts are discussed in research paper. Unfortunately, the skull was split when the amber was cut (Figs. 1C; 2A-D). The ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT rostrum is preserved in one section and the neck and most of the braincase in the other.

  1. Skull
  2.  Neck
  3. Partial wing
  4. Partial hind limbs
  5. Integumentary structures
  6. Head and neck
  7. Partial wing
  8. Partial hind limbs
  9. Partial tail
  10. Taxonomic Assessment
  11. Ontogenetic assessment

Click here to view complete report on this amber specimen XING + 2017 Enantiornithine hatchling in Burmese amber_ ACCEPTED VERSION

Source: http://terratreasures.com

 

 

The World Most Expensive Gemstones SOLD EVER

Pink Star diamond sells for $71.2 million, take a look at the world’s most expensive gemstones

59.60 Carat pink star diamond has broken the world record. It was sold by Sotheby’s in Hong Kong in $71.2 million.

The Pink Star Diamond took 2 years to cut after the best gem cutters in the world studied it to reveal the best possible gemstone. It was auctioned last year for $83 Million however the buyer of the gemstone was not able to complete the payment.

 

Blue Belle Sapphire of Asia – 11.52 million Pound

Sunrise Ruby – 19.6 million Pound

The Sunrise Ruby” was named after a poem by Rumi, a 13th century Persian poet, who gave the most powerful description to the beautiful stone of ruby:
“… a ruby held up to the sunrise.
Is it still a stone, or a world made of redness? It has no resistance to sunlight. The ruby and the sunrise are one…”

White Diamond: Oval Cut D Flawless Type IIa

Colombian Emerald – 43 million Pound

Earlier, the most expensive gemstones were Diamonds, Sapphrie and Rubies. Until recently the magic $1 million per carat mark was only achieved by colored Diamonds. With the sale of the Sunrise Ruby the beautiful red gemstone has joined the exclusive club.

The Most Expensive Gemstones sold

Blue Diamonds

  • Blue Moon Diamond – 12.03cts – $4,028,940.81 per ct
  • Oppenheimer Blue Diamond – 14.62cts – $3,932,968.54
  • Mellon’s fancy vivid blue – 9.75cts – $3,343,589.74 per ct
  • DeBeers Millennium Jewel 4 – 10.10cts – $3,148,514 per ct
  • Winston Blue – 13.22cts – $1,799,952.50 per ct
  • Ocean Dream – 5.5cts – $1,599,752.18 per ct

Red Diamonds

  • Moussaieff – 2.09cts – $2,438,216.27 per ct

Orange Diamonds

  • The Orange – 14.82cts – $2,398,151.89 per ct

Pink Diamonds

  • Unique Pink – 15.38cts -$2,054,616.85
  • Graff Pink – 24.68cts – $1,863,857.37 per ct
  • Pink Star – 59.6cts – $1,194,603.87 per ct

Ruby

  • Sunrse Ruby – 25.59cts – $1,188,745.60 per ct
  • Graff Ruby – 8.62cts – $994,199.54 per ct
  • Burmese Ruby – 6.04cts – $546,357.62 per ct
  • Burmese Ruby – 32.08cts – $208,852.87 per ct

Sapphire

  • Jewel of Kashmir – 27.68cts – $243,702.60 pre ct
  • Unamed – 35.09cts – $210,844.17 per ct
  • Blue Belle of Asia – 392.52cts – $44,063.48 per ct

Padparchasa Sapphire

  • Unnamed – 14.65cts – $52,965.94 per ct

Spinel

  • Hope Spinel – 50.13cts – $29,217.26 per ct

Diamonds, and other big three gems, Ruby, Sapphire and Emeralds are breaking the auction records. There are other also which are poplar among buyers. They are Pearls, spinel, jadeite, alexandrite, and other gems are also quite popular among buyers.

A Giant Jade Stone Weighing 175 tonnes uncovered in Myanmar

According to BBC report and other authentic media, a giant jade stone has been unearthed in Myanmar. The stone is 4.3m (14ft) high and 5.8m (19ft) long, and is reportedly worth an estimated $170m (£140m).

It was found in a mine in the jade-producing Kachin state, in the north of the country.

Local politician U Tint Soe said the piece of jade was as big as two small houses.

“I assume that it is a present for the fate for our citizens, the government and our party as it was discovered in the time of our government. It’s a very good sign for us,” he said.

Myanmar, also known as Burma, is the source of nearly all of the world’s finest jadeite, a near-translucent green stone. Myanmar half of the GDP is depending upon Jade. China is its biggest market as Chinese takes jade as ” stone of heaven”.