TECHNICAL FIELD
[0001] The present subject matter relates, in general, to techniques for
processing gemstones.
BACKGROUND
[0002] Generally, unpolished gemstones are subjected to various
machining operations, such as faceting, to obtain polished gemstones. Further, faceting is a process of creating flat surfaces, called facets, on various portions of the gemstone by removing excess material from the gemstone. Conventionally, faceting can be achieved using a cutting machine, such as a Scaife machine, in which the gemstone may be mounted on a holder of the cutting machine by the operator, such that an unpolished surface of the rough gemstone is positioned at a predetermined angle with respect to a spinning wheel of the cutting machine. Thereafter, the unpolished surface of the rough gemstone may be pressed against the spinning wheel to cut facet on the unpolished surface. Generally, prior to faceting, unpolished gemstone may be grouped manually to form a batch and stored based on their parameter, such as weight geometry, of clarity so that the unpolished gemstone having same parameters can be processed as same batch.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.

[0004] Fig. 1 illustrates a gemstone sorting unit for sorting rough
gemstones, in accordance with an implementation of the present subject matter;
[0005] Fig. 2 illustrates another view of the gemstone sorting unit for sorting
rough gemstones, in accordance with one implementation of the present subject matter;
[0006] Fig. 3 illustrates a block diagram of a gemstone processing machine
200, in accordance with one implementation of the present subject matter; and
[0007] Fig. 4 illustrates a method for batch processing a plurality of rough
gemstones, in accordance with one implementation of the present subject matter.
DETAILED DESCRIPTION
[0008] Unpolished or rough gemstones, such as diamonds, are subjected
to various polishing processes, such as planning, sawing, bruting, faceting, conning, or the like to obtain polished gemstones. Generally, multiple rough gemstones are processed in a batch in which each rough gemstone in the batch is processed individually. In one example, during the planning operation, the rough gemstone may be subjected to a scanning process to estimates physical attributes and other parameters associated with a finished gemstone that will be formed from the rough gemstone. Once the planning is done, estimated physical attributes and other parameters are saved in a computer readable medium and the rough gemstone are sent for cutting and faceting operation. During the cutting process, the rough gemstones are scanned again and are then fed to a cutting machine. After going through the cutting operation, unpolished or semi-finished gemstones are obtained. The obtained gemstones

after cutting are then collected in a tray or any suitable storage and then finally sent for the polishing operation.
[0009] Conventionally, prior to the polishing operation, the gemstones are
once again scanned individually to obtain parameters necessary for polishing the gemstones. An operator may feed the parameters into a polishing machine that forms crown and pavilion of the predetermined size based on the fed parameters. The scanning process is performed using different image processing techniques which generates a 3-D image of the gemstones. However, the operational cost of the whole process increases substantially due to multiple instances of scanning performed in the conventional techniques. In other words, even though performing multiple image scans of the gemstones ensures an efficient and better yield of the gemstones, the return on investment on the gemstone given for the entire process is substantially low. The cost and time involved in producing the finished gemstones is high, mainly due to multiple scanning of the gemstones. Therefore, such techniques may be resource intensive as identifying each rough gemstone may need additional equipment to perform image processing technique thereby adding to the overall cost of the gemstone processing technique. Moreover, identifying the rough gemstone may add to the time of the processing the rough gemstone.
[00010] In few other conventional techniques, to strike a balance between
the quality of the gemstone and the cost of manufacturing, the gemstones, at the time of polishing, may not be scanned again. For example, all gemstones may be cut based on a standard angle of crown and pavilion, and, in most cases, the crown and pavilion angle may be different from the ones that they are actually supposed to be polished based on, for instance, determined based on estimated parameters of the rough gemstone. Therefore, when processed with using the predefined parameters, the finished gemstone, so obtained, may have different size and weight than the estimated physical attributes. In some

instances, the weight of the finished gemstone may be lesser than the estimated weight. In other words, there is loss of material that lowers the yield of the gemstone processing operation. Therefore, conventional gemstone processing techniques are either less accurate or time consuming and expensive, and in either case, do not provide good yield of finished gemstone.
[00011] To this end, techniques for sorting rough gemstone are described.
The technique of sorting based on the present subject matter automatically sorts the rough gemstone based on a set of processing parameters and may form different batches of the rough gemstone so that each batch containing the rough gemstone of similar processing parameters can be processed. For instance, such a sorting may be done at or immediately after the planning phase so that there is no need to re-scan the gemstone at any other stage again, as will be explained later.
[00012] According to an example, the rough gemstone may be fed to a
gemstone sorting unit for sorting the rough gemstone. In one example, the gemstone sorting unit may include a plurality of bins, and each bin consists of a group of rough gemstones, where the group or bin is associated with one of many processing parameters that can be used to sort the rough gemstone. In one example, the rough gemstone may be sorted based on a set of processing parameters obtained from planner machine. In one example, the set of processing parameters can include diameter of gemstone, and angle of crown, table, girdle, pavilion, etc. In the case for instance, that one of the processing parameters can be a predefined angle of crown and pavilion the gemstone sorting unit may identify the predefined angle of the crown and pavilion for the rough gemstone based on the associated processing parameter. Once the predefined angle of crown and pavilion is identified, the gemstone sorting unit may sort the rough gemstone into one of the bins. The gemstone sorting unit may identify the predefined angle of the crown and pavilion and, accordingly,

can form different groups or bins of the rough gemstones for further use. Further, each group or bin may be processed separately to obtain the finished gemstones.
[00013] According to an example, since the gemstone sorting unit sorts the
gemstones prior to material removal operation such that the rough gemstones that are to be cut based on same processing parameters, such as predefined angles of crown and pavilion, are grouped together in a bin. Therefore, the rough gemstones of similar processing parameters are processed together based on the same processing parameters. As a result, the loss of material may be reduced and the yield of the gemstone process is increased since the gemstone processing parameters are not required to be changed for each gemstone. Moreover, the finished gemstone so obtained are of better quality. Also, multiple scanning of the gemstones is inhibited which results in decrease in operational cost and time. The present subject matter, thus provides a more balanced approach for planning, cutting and polishing the gemstones.
[00014] These and other advantages of the present subject matter would be
described in greater detail in conjunction with the following figures. While aspects of a gemstone sorting unit for processing rough gemstone can be implemented in any number of different configurations, the embodiments are described in the context of the following device(s) and method(s).
[00015] Fig 1 illustrates a gemstone sorting unit 100 for sorting rough
gemstones, in accordance with an implementation of the present subject matter.
[00016] According to an example, the gemstone sorting unit 100 may include
a base 102 to support other components of the gemstone sorting unit 100. In one example, the base 102 may be mounted on a mounting surface by means of fasteners pass through holes 102-1, 102-2 of the base 102. The gemstone

sorting unit 100 may include a rotating disc 104 mounted on the base, such that the rotating disc 104 rotates on the base 102 along an axis (not shown). The gemstone sorting unit 100 may include a plurality of bins 106-1, 106-2, 106-3, 106-4, 106-5, 106-6, 106-7, 106-8, 106-9, and 106-10, referred to as 106 hereinafter. Further, each bin 106 is associated with a group of rough gemstones, where the bin 106 or group may correspond to a set of processing parameters, such as predefined angle of crown and pavilion of a finished gemstone, to be formed from the rough gemstone. In one example, the gemstone sorting unit 100 may include a drive mechanism to rotate the rotating disc 104. The drive mechanism may include a driver 108, and a drive 110, such as a belt drive, to impart rotation to the rotating disc 104. In one example, the driver 108 can be, but not limited to, a PLC controlled electric motor, a stepper motor, an induction motor, or the like. In the illustrated example, the driver 108 may be coupled to the drive 110 and the drive may be coupled to a pulley 112, which is attached to the rotating disc 104.
[00017] According to an example, the gemstone sorting unit 100 also
includes a feeder 114 that feeds the rough gemstone to one of the plurality of bins 106. For instance, the feeder 114 may be installed overhead using a feeder holder 116, such that adequate gap between a bottom end of the feeder 114 and top of the bins 106 so that the feeder 114 does not impede movement of the bin 106 when the rotating disc 104 rotates the bin 106. In operation, the feeder 114 may allow the rough gemstone to tunnel towards one of the bins 106 positioned underneath the feeder 114. The gemstone sorting unit 100 may also include a sensor 118 that may sense a rotational orientation of the rotating disc 104. In one example, the sensor 118 can be, but not limited to, an optical sensor, an infrared sensor, or the like. In operation, the sensor may sense rotational orientation of the rotating disc 104 in order to determine a degree by which the rotating disc 104 should be rotated to position one of bins 106

underneath feeder 114. Further, the gemstone sorting unit 100 may also include an image capturing device (not shown) to capture images of the rough gemstone. The image capturing device may capture a plurality of images of the rough gemstone in various orientations. In one example, the image capturing device may be a camera or a video recorder.
[00018] The gemstone sorting unit 100 may also include a controller (not
shown in Fig.) for controlling the operation of the gemstone sorting unit 100 for sorting the rough gemstone. According to the illustrated aspect, the controller includes processor(s) which may be implemented as microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) may fetch and execute computer-readable instructions stored in a memory (not shown) coupled to the processor(s) of the controller. The memory may include any non-transitory computer-readable storage medium including, for example, volatile memory (e.g., ram), and/or non-volatile memory (e.g., eprom, flash memory, nvram, memristor, etc.). The memory may be internal or external to the controller. The functions of the controller may be provided through the use of dedicated hardware as well as hardware capable of executing computer-readable instructions.
[00019] The controller is coupled to the sensor 118, the image capturing
device and the driver 108. The controller receives the images captured by the image capturing device and may generate 3D profiles of the various rough gemstones. Based on the generated 3D profiles, the controller may obtain a set of processing parameters and may identify a bin 106 based on the set of processing parameters. For example, the controller may identify angles of crown and pavilion and, based on the identification, may select a bin 106 which matches with the identified angles of crown and pavilion. The controller may

receive a position signal from the sensor 118 and determine the orientation of the rotating disc 104. Based on the orientation of the rotating disc 104, the controller determines the position of the selected bin 106 that matches with identified angles of crown and pavilion. Accordingly, the controller may provide signals to the driver 108 to rotate the rotating disc 104 by a suitable angle so that the rough gemstone reaches the selected bin 106.
[00020] Fig. 2 illustrates another view of the gemstone sorting unit 100, in
accordance with one implementation of the present subject matter. As stated earlier, each bin 106 may store the rough gemstone that will be processed based on the set of processing parameters, such as predefined angle of crown and pavilion. For instance, the bin 106-2 may store the rough gemstone that will be cut to obtain finished gemstone that has a crown angle of 340 and pavilion angle of 400, referred to as C34-P40. Similarly, the bin 106-3 may store rough gemstone that will have value of crown and pavilion as C34-P41, the bin 106-4 may store rough gemstone that will have a value of crown and pavilion as C34-P42, and so on.
[00021] In the illustrated example, the rotating disc 104 may have an initial
position, referred to as a homing position in which the bins 106 are not positioned based on the angle of crown and pavilion. For instance, the homing position may be a position when the bin 106-1 is positioned underneath the feeder 114. In addition, the homing position may attain a plurality of parking positions corresponding to a position in which one of the bins 106 is positioned underneath the feeder 114.
[00022] Initially, the rough gemstone may be mounted on a dope and may
be fed to a separating mechanism where the rough gemstone is separated from the dope. The controller obtains a set of processing parameters of the rough gemstone based on 3D profiles generated from the images captured by the image capturing device. The controller identifies a bin 106 from the plurality

of bins 106 which is suitable to receive the rough gemstone. In addition, the controller may receive the position signal from the sensor 118 to ascertain whether the orientation of the rotating disc 104 to determine position of identified bin 106 corresponding to the set of processing parameters. After determining the position, the controller operates the drive mechanism to rotate the rotating disc 104 by a suitable angle so that the identified bin 106 is positioned underneath the feeder 114. The feeder 114 then feeds the rough gemstone to the identified bin 106 at a release position. In other words, the release position is a position of the rotating disc 104 at which one of the bins 106 is configured to receive the rough gemstone.
[00023] According to an example, the controller may determine the
predefined value of crown and pavilion based on the 3D geometry of the rough gemstones. For instance, the controller may identify the value of crown and pavilion as C34-P42. Accordingly, the controller may actuate the driver 108 to rotate the rotating disc 104 by a predefined degree, such that the bin 106-4 underneath the feeder 114. Once positioned, the separating mechanism may drop, shown by downward arrow in Fig 2, the rough gemstone into the upper end of the feeder 114 that guides the rough gemstone to the bin 106-4. Once the rough gemstone is dropped in the bin 106-4, the controller may again the actuate the rotating disc 104 to re-position the rotating disc 104 at the homing position. Thereafter, the gemstone sorting unit 100 may receive next rough gemstone along with the associated processing parameters. Thereafter, the controller may again determine the predefined value of crown and pavilion and accordingly, may actuate the driver 108 to rotate the rotating disc 104 to position a corresponding bin 106 underneath the feeder 114. Thereafter, the separating mechanism may separate the rough gemstone from the dope and the dope may be allowed to fall into the positioned through the feeder 114. This operation may be repeated until all the rough gemstones are sorted. Once all

the rough gemstones are sorted, each bin 106 may be dismounted from the rotating disc 104 in one bin may processed. Thereafter, the rough gemstone of next bin 106 may be processed. Since, the rough gemstone that are in same bin are processed together, chances of cutting the rough gemstone based on different predefined values of crown and pavilion is alleviated. As a result, the loss of material is reduced, and yield of the gemstone processing operation is increased. Also, the rough gemstones are scanned only once to determine the set of processing parameters, thereby resulting in a significant decrease in operational time and cost of the gemstone sorting process.
[00024] Once the rough gemstones are sorted, each bin is processed
separately. For instance, the sorted gemstones in one of bin are sent to a cutting machine where the sorted gemstone are cut based on the processing parameters on which the rough gemstones were sorted. Once rough gemstones in the bin are processed by the cutting machine, the rough gemstones are sent to a polishing unit where each rough gemstone is processed based on other processing parameters that are identified by the planning unit to obtain the finished gemstone. This process is repeated for the next bin until all bins are processed.
[00025] Fig. 3 illustrates a block diagram of a gemstone processing machine
200, according to an example of the present subject matter. In one example, the gemstone processing machine 200 may include a planner machine 300 which further includes a gemstone sorting unit 100. In said example, the gemstone sorting unit 100 can further include a base 102, a rotating disc 104 having a plurality of bins 106, a drive mechanism, a sensor 118, an image capturing device, and a controller.
[00026] In another example, however, the gemstone sorting unit 100 can be
a separate unit than the planner machine 300 in the gemstone processing machine 200. In the latter example, for instance, the gemstone sorting unit 100

and the planner machine 300 may share their resources. For instance, the gemstone sorting unit 100 and the planner machine 300 may have a common image capturing device as well as a common controller.
[00027] In operation, as explained above, the image capturing device may
be included in the planner machine 300. Accordingly, the planner machine obtains the plurality of images of the rough gemstones and transmits the images to the controller of the gemstone sorting unit 100. In an example, the planner machine 300 may obtain 3D profiles of the rough gemstones and transmit the 3D profiles to the controller of the gemstone sorting unit 100. In another example, the gemstone sorting unit 100 may be included as a separate unit of the gemstone processing machine 200. In said example, the image capturing may be included as a part of the gemstone sorting unit 100. The gemstone sorting unit 100 on the basis of the 3D profiles of the rough gemstones identifies a set of processing parameters, such as, angles of crown and pavilion. Based on the set of processing parameters, the gemstone sorting unit 100 sorts the rough gemstones into one of the plurality of bins 106. In other words, the rough gemstones that are present in a particular bin have identical processing parameters. After the sorting process is complete, the plurality of bins 106 undergo different material removing operations. The material removal operation is performed on each of the rough gemstones in a bin based on the common processing parameter. In an example, the gemstone processing machine 200 may include other units to perform material removal operations, such as a cutting unit (not shown) for performing a cutting operation on the rough gemstones and a polishing unit (not shown) for performing a polishing operation on the cut gemstones received from the cutting unit.
[00028] Fig. 4 illustrates a method for batch processing a plurality of rough
gemstones, according to an example of the present subject matter. The method may be described in the general context of computer executable instructions.

Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, engines, functions, etc., that perform certain functions or employ certain abstract data types. The method may also be practiced in a distributed computing environment where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.
[00029] The order in which the blocks in the method are described is not
intended to be construed as a limitation, and any number of the described blocks can be combined in any order to employ the method, or an alternative method. Additionally, individual blocks may be deleted from the method without departing from the scope of the subject matter described herein. Furthermore, the method can be employed in any suitable hardware, software, firmware, or combination thereof. In one example, the method may be implemented by the gemstone processing machine 200 and the various components thereof. For the sake of brevity, the components and details associated with the device 100 as described in Figure 1, Figure 2, and Figure 3 have not been repeated.
[00030] At block 202, includes obtaining a plurality of images of a rough
gemstone from amongst the plurality of the rough gemstone in different orientations of the rough gemstone. The plurality of images may be obtained from an image capturing device, and the image capturing device may be included as a part of the planner machine 300 or the gemstone sorting unit 100.
[00031] At block 204, a three-dimensional (3D) profile of the rough gemstone
is generated based on the plurality of images of the rough gemstone. In an example, the 3D profiles may be generated by the planner machine 300 or by the controller of the gemstone sorting unit 100.

[00032] At block 206, a set of processing parameters for the rough gemstone
is obtained based on the 3D profile of the rough gemstone. The controller of the gemstone sorting unit 100 may identify the set of processing parameters.
[00033] At block 208, the rough gemstones are sorted into a group or a bin
106 from amongst a plurality of groups or bins 106 based on the set of processing parameters. The sorting may be performed by the controller for each of the plurality of rough gemstones to sort the plurality of rough gemstones into one of the plurality of groups or bins 106 based on the set of processing parameters of each of the plurality of rough gemstones.
[00034] At block 210, after completion of sorting process, a material removal
operation is performed on each group or bin 106 from the plurality of groups or bins 106. The material removal operation is performed on each rough gemstone in the group or bin based on a set of common processing parameters for the group or bin. In an example, the material removal operation may be a cutting operation to be performed on a cutting machine or a polishing operation performed by a polishing machine. In one example, the polishing operation is performed after the cutting operation.
[00035] Although aspects of assorting gemstones have been described in a
language specific to structural features and/or methods, it is to be understood that the subject matter is not limited to the features or methods described. Rather, the features and methods are disclosed as examples of assorting gemstones.

I/We Claim:
1. A gemstone sorting unit (100) for a gemstone processing machine (200)
to sort rough gemstones, the gemstone sorting unit (100) comprising:
5 a base (102);
a rotating disc (104) mounted on the base (102), the rotating disc (104)
comprising a plurality of bins (106) to each receive a predefined size of rough
gemstones, the plurality of bins (106) positioned at the circumference of the
rotating disc (104) formed at an angular distance along the circumference, each
10 bin (106) on the rotating disc (104) being configured to receive a rough
gemstone at a release position of the gemstone sorting unit (100);
a sensor (118) to determine orientation of the rotating disc (104);
a drive mechanism operably coupled to the rotating disc to index the rotating disc (104);
15 an image capturing device to capture a plurality of images of the rough
gemstones in different orientations with respect to the image capturing device; and
a controller operably coupled to the sensor (118), the drive mechanism and the image capturing device, wherein the controller is configured to:
20 generate 3D profile for the rough gemstones based on the
plurality of images captured by the image capturing device;
obtaining a set of processing parameters for each of the gemstones from the generated 3D profile of the rough gemstone;
identify a bin from the plurality of bins (106) for the rough
25 gemstone based on the set of processing parameters;

determine orientation of the rotating disc (104) based on information received from the sensor (118); and
control the drive mechanism to index the rotating disc (104) to move the identified bin (106) to the release position.
2. The gemstone sorting unit (100) as claimed in claim 1, wherein the gemstone sorting unit (100) is integrated with a planner machine (300).
3. The gemstone sorting unit (100) as claimed in claim 1, wherein the drive mechanism comprises a driver (108) and a drive (110) coupled to the driver (108), wherein the drive (110) may be further coupled to a pulley (112) attached to the rotating disc (104).
4. The gemstone sorting unit (100) as claimed in claim 1, wherein the image capturing device is a camera or a video recorder.
5. The gemstone sorting unit (100) as claimed in claim 1, wherein the gemstone sorting unit further includes a feeder (114) to feed rough gemstones to one of the plurality of bins (106) at the release position.
6. The gemstone sorting unit (100) as claimed in claim 5, wherein a feeder holder (116) is configured to hold the feeder (114) at a gap from a top surface of the plurality of bins (106).
7. The gemstone sorting unit (100) as claimed in claim 1, wherein the sensor (118) is an optical sensor or an infrared sensor.

8. The gemstone sorting unit (100) as claimed in claim 1, wherein the sorting operation is followed by a material removing operation of the rough gemstones.
9. The gemstone sorting unit (100) as claimed in claim 8, wherein the material removing operation is a cutting operation.
10. The gemstone sorting unit (100) as claimed in claim 8, wherein the material removing operation is a polishing operation.
11. The gemstone sorting unit (100) as claimed in any one of claims 8, wherein the material removing operation comprises a cutting operation followed by a polishing operation.
12. A method of batch processing a plurality of rough gemstones, the method comprising:
obtaining a plurality of images of a rough gemstone from amongst the plurality of the rough gemstone in different orientations of the rough gemstone;
generating a three-dimensional (3D) profile of the rough gemstone based on the plurality of images of the rough gemstone;
obtaining a set of processing parameters for the rough gemstone based on the 3D profile of the rough gemstone;
sorting the rough gemstone into a group from amongst a plurality of groups based on the set of processing parameters, wherein the sorting is performed for each of the plurality of rough gemstones to sort the plurality of rough gemstones into one of the plurality of groups based

on the set of processing parameters of each of the plurality of rough gemstones;
performing a material removal operation on each group from the plurality of groups, wherein the material removal operation is performed on each rough gemstone in the group based on a set of common processing parameters for the group.
13. The method as claimed in claim 12, wherein the material removing operation is a cutting operation.
14. The method as claimed in claim 12, wherein the material removing operation is a polishing operation.
15. The method as claimed in claim 12, wherein the material removing operation comprises a cutting operation followed by a polishing operation.