questions + answers
What is the difference between 9ct and 18ct?
9ct and 18ct refers the amount of gold content which is in the respective metal. Think of the gold metals being made up of 1000 parts. In 24ct gold 1000 of those parts are made up of fine gold. In 9ct, 375 parts of the metal is made up of fine gold and the remaining 625 parts of various alloys. That is why you see 9ct being stamped with either 9ct or 375 In 18ct, 750 parts of the metal is made up of fine gold and the remaining 250 parts of various alloys. That is why you see 18ct being stamped with either 18ct or 750. The stamps only indicate the carat of metal. They do not indicate the colour of the metal. So for example an 18ct yellow gold ring would have a stamp of 750, as would an 18ct white gold ring.
Is 9ct harder than 18ct?
Contrary to popular belief 18ct is harder than 9ct gold. 9ct has a Vickers hardness of 120 and 18ct has a Vickers hardness of 125. This shows 18ct as harder, but the difference is so slight that in practical terms 9ct and 18ct are much the same in terms of hardness.
What are the differences between the white coloured precious metals?
- Platinum 950: The pros are that it is naturally white, hypoallergenic and more pure (95%). It is noticeably heavier than other precious metals. Platinum maintains it's white colour forever which eliminates the need for rhodium plating. The cons of platinum is that it is the softest of the precious metals, and therefore it scratches the easiest. It is also much more dense metal then the other white metals, so you need a lot more of it to create a finished piece.
- Palladium 950: The pros are that it is naturally white, hypoallergenic, more pure (95%), and it is substantially less expensive than platinum. Palladium maintains its white colour forever which eliminates the need for rhodium plating. The cons are that it is only a little harder than platinum so it will scratch easier than white gold alloys.
- 18ct White Gold: The pros are that is more pure than 9ct white gold (75% vs 37%), and it is more scratch resistant than palladium or platinum. Even with the premium metal that Ryley Jewellery Creations use, the cons are that it has a grey tinge so it requires rhodium plating to be pure white in colour.
- 9ct White Gold: The pros are that it is more cost effective than 18ct gold as it contains less fine gold in its composition. The cons are it often contains nickel to which 10% of women are allergic to. Even with the premium metal that Ryley Jewellery Creations use, 9ct white gold will still have a grey tinge so it requires rhodium plating to be pure white in colour.
What is rhodium plating?
Rhodium is a silvery-white precious metal and a member of the platinum family. It is the material most often used to plate jewellery because of its highly-reflective finish, hardness, and corrosion resistance. It is also hypoallergenic, and will prevent yellow and white gold from leaving a greenish tinge on the skin.
What are the safest way to set diamonds and gemstones?
Generally the safest way to set diamonds and gemstones is in a way that the metal completely surrounds the stone. These style of settings are often called rubover, rub-in, hammer, flush or gypsy set. However, any of the other styles of setting (including claw) are totally acceptable if they are set correctly, worn on the body or finger correctly and the jewellery checked by a qualified jeweller at least once a year.
What are the difference types of opals?
- Black Opal - Black opal is characterised by a dark body tone causing brightness of colour which is unmatched by lighter opals. Black Opals are usually mined in Lightning Ridge, New South Wales, and are the most famous, and sought-after type of opal.
- White Opal - Also known as 'milky opal', white opal features light white body tones, and is mined in South Australia. White opal is more common and because of its body tone, generally does not show the colour as well as black opal.
- Boulder Opal - Boulder opal forms on ironstone boulders in Queensland. This type of opal is often cut with the ironstone left on the back, as the opal seam is usually quite thin. Leaving the ironstone on the back means that boulder opal can be very dark and beautiful in colour.
- Crystal Opal - Crystal opal is any of the above kind of opal which has a transparent or semi-transparent body tone. Crystal opal can have a dark or light body tone, leading to the terms "black crystal opal" and "white crystal opal".
- Fire Opal - One of the world’s newest gemstone discoveries was found here in Australia. The Australian Fire Opal. The main deposit of fire opals however are the Mexican Fire Opal, mined in Mexico, which usually has a distinct orange colouring.
- Yowah Nuts - Found in the far South Western mines at Yowah in Queensland, Yowah nuts are ironstone concretions resembling 'nuts' which contain precious opal in their centre. Upon cracking or slicing the Yowah nut, the precious opal is revealed.
- Synthetic opal - Opaline silica produced in the laboratory and having a similar structure to that of precious opal. The most well-known form of synthetic opal is Gilson Opal.
- Doublets and triplets -These are partially man-made stones, consisting of only a paper-thin slice of opal cemented to a black backing. Triplets have a clear quartz or glass capping over the top to magnify the colour, protect the stone, and give it a cabochon (domed) appearance. The idea of doublets and triplets is to imitate valuable black opals at a fraction of the cost.
Do Sapphires only come in blue?
Sapphires come in a wide range of colours, and each colour has its own quality variations. In general, the more intense the colour, the more valuable the stone. The major fancy sapphire colour categories are padparadscha (salmon or sunset), pink and purple, orange and yellow, green, colourless and black.