great gem and company
|Dimensions (mm)||8 x 6 x 3mm|
|Weight (carats)||0.7 carats|
INSURANCE TERMS : INSURANCE IS RECOMMENDED
6 $ for the first 100 $ dollars
6 $ for every 100 $ dollars thereafter
If you choose not to take insurance ,we cannot be held liable if the parcel gets lost or damage in transit.
COMBINE SHIPPING TERMS : We offer as follow combine shipping conditions : paying 15 $ dollars for two or more items purchased in a period time of 3 days from the date of your first item purchased,please
you need to pay all the wins at the same time, due the OA sistem works automatically.
PAYMENT POLICE : We kindly ask to set your wins items in 3 days from the date of your win.
REFUND TERMS : Should you not be satisfied the item can be returned for a full refund within ten daysof notification of any aforesaid problems.We recommended that you use a carrier that can provide you with aproof of delivery ,for your protection.
N.B. It is not possible to refund your item after you leaved negative or neutral feedback .We are open to solve any kind of problem you could have with the item received.So please before leaving a negative feedback contact
us we will find a right solution.
SHIPPING TERMS : Monalisa undertakes to make shipment within 7 days of payment.
Our Cabochon / Freeform stones have been cut to exalting the stone’s existing colors and patterns. This means that each stone is undoubtedly unique albeit slightly asymmetrical.
All our stones are untreated and photographed when they’re bone-dry.
An opal is a hydrated form of silica with a water content ranging from 3 to 21%.Indeed, it is this permeability to water that makes it a hydrophile.
Opals are deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt. Precious opals show a variable interplay of internal colors.
At microscopic scales, precious opal is composed of silica spheres some 150 to 300 nm in diameter in a hexagonal or cubic close-packed lattice. These ordered silica spheres produce the internal colors by causing the interference and diffraction of light passing through the microstructure of the opal.
This diffraction means that opals can be grouped into two main categories according to:
When an opal’s silicon spheres in the same strata have a diameter close to that of a visible light wave (under a micron) and these spheres are all the same, there is light diffraction and a wonderful array of colors becomes visible depending on the angle of observation. What’s more: the diameter of these spheres produces the dominant colors given off by these stones.
On the other hand, when these silicon spheres have different sizes (some greater and some smaller than that of the wave length of visible light), there is no diffraction and the opal, instead of being iridescent becomes silent. This means that there is only the second characteristic of a precious opal, its opalescence, or better a somewhat milky look that can be seen when most of these stones are subject to light.
Another category of opals is the hydrophane. The hydrophane opal is a particular variety of opal that, having lost its water, appears murky and insignificant. It is, however, surprising what happens to this stone when it is immersed in water (time varies from minutes to some days): its refraction index goes from 1.40 to 1.44 and being rehydrated is almost unrecognizable due to its newly found almost impeccable transparency and splendid hues of iridescence. However, this treatment is skin-deep. When referring to the hydrophane opal, we’re therefore talking about a category of this mineral that is not sparkly, is highly porous and becomes transparent when immersed in water.
Salve! 781396 did arrive safely just now. Very nice dendritic Welo with good Colours. All at best! Until next time. Ciao! Waldi
|Starts||28th Apr 2018 9:54am PDT|
|Registered Shipping||$15.00||21 Days|
|Standard Shipping - Untracked||$12.00||21 Days|
|Shipping Insurance all providers $6.00 (optional)|