Martin Braun

MATERIAL
GOLD. Gold is the most malleable and ductile metal; a single gram can be beaten into a sheet of one square meter, or an ounce into 300 square feet. Gold leaf can be beaten thin enough to become translucent. The transmitted light appears greenish blue, because gold strongly reflects yellow and red. Gold readily forms alloys with many other metals. These alloys can be produced to increase the hardness or to create exotic colors. Native gold contains usually eight to ten percent silver, but often much more — alloys with a silver content over 20% are called electrum. As the amount of silver increases, the color becomes whiter and the specific gravity becomes lower. Gold is a good conductor of heat and electricity, and is not affected by air and most reagents. Heat, moisture, oxygen, and most corrosive agents have very little chemical effect on gold, making it well-suited for use in coins and jewelry; conversely, halogens will chemically alter gold, and aqua regia dissolves it via formation of the chloraurate ion. PLATINUM. When pure, the metal appears greyish-white and firm. The metal is corrosion-resistant. The catalytic properties of the six platinum family metals are outstanding. For this catalytic property, platinum is used in catalytic converters, incorporated in automobile exhaust systems, as well as tips of spark plugs. Platinum‘s wear- and tarnish-resistance characteristics are well suited for making fine jewelry. Platinum is more precious than gold. The price of platinum changes along with its availability, but its price is normally slightly less than 150% of the price of gold. In the 18th century, platinum‘s rarity made King Louis XV of France declare it the only metal fit for a king. Platinum possesses high resistance to chemical attack, excellent high-temperature characteristics, and stable electrical properties. All these properties have been exploited for industrial applications. Platinum does not oxidize in air at any temperature, but can be corroded by cyanides, halogens, sulfur, and caustic alkalis. This metal is insoluble in hydrochloric and nitric acid, but does dissolve in the mixture known as aqua regia (forming chloroplatinic acid). DIAMONDS. A diamond is, technically speaking, a transparent crystal of tetrahedrally bonded carbon atoms and crystallizes into the face centered cubic diamond lattice structure. Diamonds have been adapted for many uses because of the material‘s exceptional physical characteristics. Most notable are its extreme hardness, its high dispersion index, and extremely high thermal conductivity (900 – 2320 W/m K), with a melting point of 3820 K (3547 °C / 6420 °F) and a boiling point of 5100 K (4827 °C / 8720 °F).[5] Naturally occurring diamonds have a density ranging from 3.15 to 3.53 g/cm³, with very pure diamond typically extremely close to 3.52 g/cm³. Diamond is the hardest natural material known to man; hardness is defined as resistance to scratching. Diamond has a hardness of 10 (hardest) on Mohs scale of mineral hardness. Diamond‘s hardness has been known since antiquity, and is the source of its name. SAPPHIRE CRYSTAL. What exactly is synthetic sapphire? It is a very hard, transparent material made of crystallizing aluminum oxide at very high temperatures. Chemically, synthetic sapphire is the same as the natural sapphire used in jewelry, but without the coloring agents that give the gemstone its various hues. When it is heated, the synthetic sapphire forms round masses that are sliced into pieces with diamond-coated saws. These disks are then ground and polished into watch crystals. Sapphire is one of the hardest substances on earth. It measures 9 on the Mohs scale, which is a system for rating the relative hardness of various materials. Watch crystals made of synthetic sapphire are often marketed as „scratch resistant“, meaning they are very difficult - but not impossible - to scratch. Diamonds can scratch them; so can man-made materials that incorporate silicon carbide, with a Mohs rating of between 9 and 10, and are like diamond, harder than sapphire. These materials are sometimes used to make simulated-stone surfaces for furniture or walls. The watch wearer should note that accidentally scraping a sapphire crystal against such a surface could cause a scratch. PVD COATING. Physical vapor deposition (PVD) is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit thin films by the condensation of a vaporized form of the material onto various surfaces. The coating method involves purely physical processes such as high temperature vacuum evaporation or plasma sputter bombardment rather than an involving a chemical reaction at the surface to be coated as in chemical vapor deposition. The term physical vapor deposition appears originally in the 1966 book “Vapor deposition” Variants of PVD include, in order of increasing novelty: • Evaporative deposition - In which the material to be deposited is heated to a high vapor pressure by electrically resistive heating in „high“ vacuum. • Electron Beam Physical Vapor Deposition - In which the material to be deposited is heated to a high vapor pressure by electron bombardment in „high“ vacuum. • Sputter deposition - In which a glow plasma discharge (usually localized around the „target“ by a magnet) bombards the material sputtering some away as a vapor. • Cathodic Arc Deposition - In which a high power arc directed at the target material blasts away some into a vapor. • Pulsed laser deposition - In which a high power laser ablates material from the target into a vapor. PVD is used in the manufacture of items that must be very abrasive and stable against thermic exposure A lot of techniques, but the result on a watchcase is only breathtaking. A deep black long lasting colour!

MATERIAL

GOLD.
Gold is the most malleable and ductile metal; a single gram can be beaten into a sheet of one square meter, or an ounce into 300 square feet. Gold leaf can be beaten thin enough to become translucent. The transmitted light appears greenish blue, because gold strongly reflects yellow and red.
Gold readily forms alloys with many other metals. These alloys can be produced to increase the hardness or to create exotic colors. Native gold contains usually eight to ten percent silver, but often much more — alloys with a silver content over 20% are called electrum. As the amount of silver increases, the color becomes whiter and the specific gravity becomes lower.

Gold is a good conductor of heat and electricity, and is not affected by air and most reagents. Heat, moisture, oxygen, and most corrosive agents have very little chemical effect on gold, making it well-suited for use in coins and jewelry; conversely, halogens will chemically alter gold, and aqua regia dissolves it via formation of the chloraurate ion.

PLATINUM.
When pure, the metal appears greyish-white and firm. The metal is corrosion-resistant. The catalytic properties of the six platinum family metals are outstanding. For this catalytic property, platinum is used in catalytic converters, incorporated in automobile exhaust systems, as well as tips of spark plugs.
Platinum‘s wear- and tarnish-resistance characteristics are well suited for
making fine jewelry. Platinum is more precious than gold. The price of platinum changes along with its availability, but its price is normally slightly less than 150% of the price of gold. In the 18th century, platinum‘s rarity made King Louis XV of France declare it the only metal fit for a king.

Platinum possesses high resistance to chemical attack, excellent high-temperature characteristics, and stable electrical properties. All these properties have been exploited for industrial applications. Platinum does not oxidize in air at any temperature, but can be corroded by cyanides, halogens, sulfur, and caustic alkalis. This metal is insoluble in hydrochloric and nitric acid, but does dissolve in the mixture known as aqua regia (forming chloroplatinic acid).

DIAMONDS.
A diamond is, technically speaking, a transparent crystal of tetrahedrally bonded carbon atoms and crystallizes into the face centered cubic diamond lattice structure. Diamonds have been adapted for many uses because of the material‘s exceptional physical characteristics. Most notable are its extreme hardness, its high dispersion index, and extremely high thermal conductivity (900 – 2320 W/m K), with a melting point of 3820 K (3547 °C / 6420 °F) and a boiling point of
5100 K (4827 °C / 8720 °F).[5] Naturally occurring diamonds have a density ranging from 3.15 to 3.53 g/cm³, with very pure diamond typically extremely close to 3.52 g/cm³.

Diamond is the hardest natural material known to man; hardness is defined as resistance to scratching. Diamond has a hardness of 10 (hardest) on Mohs scale of mineral hardness. Diamond‘s hardness has been known since antiquity, and is the source of its name.

SAPPHIRE CRYSTAL.
What exactly is synthetic sapphire? It is a very hard, transparent material made of crystallizing aluminum oxide at very high temperatures. Chemically, synthetic sapphire is the same as the natural sapphire used in jewelry, but without the coloring agents that give the gemstone its various hues.

When it is heated, the synthetic sapphire forms round masses that are sliced into pieces with diamond-coated saws. These disks are then ground and polished into watch crystals. Sapphire is one of the hardest substances on earth. It measures 9 on the Mohs scale, which is a system for rating the relative hardness of various materials. Watch crystals made of synthetic sapphire are often marketed as „scratch resistant“, meaning they are very difficult - but not impossible - to scratch. Diamonds can scratch them; so can man-made materials that incorporate silicon carbide, with a Mohs rating of between 9 and 10, and are like diamond, harder than sapphire. These materials are sometimes used to make simulated-stone surfaces for furniture or walls. The watch wearer should note that accidentally scraping a sapphire crystal against such a surface could cause a scratch.

PVD COATING.
Physical vapor deposition (PVD) is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit thin films by the condensation of a vaporized form of the material onto various surfaces. The coating method involves purely physical processes such as high temperature vacuum evaporation or plasma sputter bombardment rather than an involving a chemical reaction at the surface to be coated as in chemical vapor deposition. The term physical vapor deposition appears originally in the 1966 book “Vapor deposition”

Variants of PVD include, in order of increasing novelty:
• Evaporative deposition - In which the material to be deposited is heated to a high vapor pressure by electrically resistive heating in „high“ vacuum.
• Electron Beam Physical Vapor Deposition - In which the material to be deposited is heated to a high vapor pressure by electron bombardment in „high“ vacuum.
• Sputter deposition - In which a glow plasma discharge (usually localized around the „target“ by a magnet) bombards the
material sputtering some away as a vapor.
• Cathodic Arc Deposition - In which a high power arc directed at the target material blasts away some into a vapor.
• Pulsed laser deposition - In which a high power laser ablates material from the target into a vapor.

PVD is used in the manufacture of items that must be very abrasive and stable against thermic exposure

A lot of techniques, but the result on a watchcase is only breathtaking. A deep black long lasting colour!