HI all,
I've recently looked at a couple of lovely larger-size OEC diamonds, both loose and in settings in antique jewelry stores. In some stones I've noticed the following phenomenon:
When wearing the stone on my hand, and looking down at it from a slight angle (so that the stone face is not facing me directly but rather facing up to the wall or ceiling) the stone is bright bright bright, white, and brilliant. However, when I tilt the stone ever so slightly to look at it head on, I can see the reflection of my head in the table facets which turns the table a little shadowy. It's not that the table goes black, like a nail head - there is still some light return. But I can literally see the reflection of my skin and hair (or my phone case if I'm taking a picture) in the table facets like a mirror, and it impacts the brightness of the stone's face. I notice this starting at a distance of about 18 inches from my face or so.
Is this the phenomenon known as obstruction? How much of this is just to be expected in old cuts (or in diamonds in general)? I'm not sure I've ever really paid attention to this before but now that I am aware of it, I notice it to some extent even in my cushion cut. But those broad table facets in the OECs seem to accentuate it. What causes this (ie, any way to tell from a stone's specs which stones might have it?). Many of the stones I have been looking at are rather deep.
I will try to post some photos showing my effort to capture the phenomenon with a camera (which was nearly impossible). In real life the shadowing is somewhat less, because instead of a big broad teal phone case three inches away, it's reflecting my skin and hair a bit further away. Anyway, any thoughts appreciated.
I've recently looked at a couple of lovely larger-size OEC diamonds, both loose and in settings in antique jewelry stores. In some stones I've noticed the following phenomenon:
When wearing the stone on my hand, and looking down at it from a slight angle (so that the stone face is not facing me directly but rather facing up to the wall or ceiling) the stone is bright bright bright, white, and brilliant. However, when I tilt the stone ever so slightly to look at it head on, I can see the reflection of my head in the table facets which turns the table a little shadowy. It's not that the table goes black, like a nail head - there is still some light return. But I can literally see the reflection of my skin and hair (or my phone case if I'm taking a picture) in the table facets like a mirror, and it impacts the brightness of the stone's face. I notice this starting at a distance of about 18 inches from my face or so.
Is this the phenomenon known as obstruction? How much of this is just to be expected in old cuts (or in diamonds in general)? I'm not sure I've ever really paid attention to this before but now that I am aware of it, I notice it to some extent even in my cushion cut. But those broad table facets in the OECs seem to accentuate it. What causes this (ie, any way to tell from a stone's specs which stones might have it?). Many of the stones I have been looking at are rather deep.
I will try to post some photos showing my effort to capture the phenomenon with a camera (which was nearly impossible). In real life the shadowing is somewhat less, because instead of a big broad teal phone case three inches away, it's reflecting my skin and hair a bit further away. Anyway, any thoughts appreciated.